I'd love to install Ubuntu as a standard standalone on my ipad, is there any way to do so?
For the time being, there is up to now, no way to install Ubuntu (or any Linux system for that matter) on the iPad as easily as rooting an Android. Since a year and half ago in an article about Linux running on Ipad (August 2011) there has been only small changes and steps to provide a final way of installing Ubuntu to an iPad (Or any other Mac hardware for that matter).
The team behind this, the iDroid team has a webpage where you can see their status and how far they have gotten: http://www.idroidproject.org/wiki/Status
Of course, at the end, you are limited to only accomplishing the boot part in the devices it supports. The good news is that, as far as the history of Linux is concerned, there is no ¨iCan´t¨, there is only I CAN! so in the future this could possibly be done in an out of the box manner.
Thanks to a link provided by mateo_salta, there is no legal way right now (There is a debate about it from the FSF) to jailbreak an iPad. The information can be read HERE.
For what it is worth, this is just another attempt from the DMCA to stop something they should not be stopping. If you buy an iPad, it is YOUR iPad. Maybe just hop into a plane out of the US, buy the iPad, do whatever you like with it and then come back ^^.
UPDATE: So here is some information regarding a neighbor I have that, apart from looking like Steve Jobs without the glasses, also knows about the idroidproject and has every Mac device since the palm. He showed me the iPad 1 and 2 and explained A LOT of stuff about how Mac works in regards to, let's say, blocking, ways of trying to root, jailbreak or any other word you would like to use to change how the system behaves or even change the actual system (Like installing Ubuntu on an iPad). So here are the key points that I could write about:
The iPad and any other new hardware needs to first be compatible or supported at least first with the Linux kernel. If not, then it will be very tough to get it working on Ubuntu. This creates a problem for the correct detection of the CPU, motherboard, video card, sound card, wireless card, battery detection and usage and any other hardware found on the device.
There is a strong force behind not allowing any way to be able to overwrite the actual system with another or any apps that can do this. Everything is very tight, sandboxed and checked to make sure it conforms to the way the iOs works. There are alternatives like Cydia but it needs the device to be jailbroken first.
There is a strong legal pressure from Mac to force any attempts to do something like installing Ubuntu on iPad be denied or very tough to do as one can see from the links above.
Since Mac focuses on a specific type of hardware and works only on a small group of devices (Compared to Linux on how open it is with hardware types), it makes it even tougher to guarantee that the new system, be it Ubuntu or any other Linux, will actually work correctly with all the hardware every time.
Since bootlace only works with Phone 2G, iPhone 3G or iPod Touch 1G and with a specific version of the iOs, it makes it the more difficult to get the iPad working in the present time (With all the points above pushing in on the problem)
With the slow development of the openiBoot project and seen how it can actually only detect the CPU used in the iPad as of this writing we can only see that it will be a long way until a proper boot, load and install procedure can be made to get any Linux distro into an iPad. Here is the image from the status page:
So it is sad to see such a strong wish against using Linux on this type of hardware and I should say such a good hardware indeed would actually enjoy Linux on it.
So sorry for the negative answer and the pessimist approach I bring to it. Most of this information is thanks to a heavy Mac user that also delves himself in the Ubuntu world and knows much about this. He almost convinced me to leave Ubuntu and jump to Mac (Mac evangelist hehe) but he also made good points (From the Mac side of course) regarding the reasons behind such a close sourced way of focusing on this devices. Not my kind of answer since I tend to look for an answer but I got curious and started asking many Mac users and well.. you can see how my answer changed to a more clear one... if I can call it clear.
Considering the incredible amount of difficulty it would take to actually get Ubuntu running on an iPad, I'd recommend taking a different approach.
Keep in mind all information I'm about to tell you will COMPLETELY VOID YOUR WARRANTY (and, as a about a week ago, is illegal in the US due to the Librarian of Congress being an idiot/group of idiots).
Running Ubuntu is theoretically possible to run on the iPad. OpeniBoot is known to run Linux kernels, especially Android.
Personally, I'd recommend booting into Android and taking a path that many with an Android tablet do - using a chroot. This involves booting into Android and sharing that kernel with a desktop operating system. This allows you to keep the touch friendly parts of an OS but also run Ubuntu on the side. For more information on running Android on iPad, take a look at The iDroid Project.
Running two OS's is far from optimal though. This is where the real tinkerers come in. I'm sure it's possible to run Ubuntu , but I haven't seen any real evidence of it being done. There's a first time for everything!
I don't own an iPad, but I do know a bit about chroot on Android. I've got the Asus TF201 and have Ubuntu 12.10 alongside Android. Although sometimes running Ubuntu directly on it would benice, sometimes it's just not realistic.
Let us know if you can get Ubuntu running on it. Otherwise, go with the iDroid method.
EDIT: It turns out the OpeniBoot doesn't work on the iPad.
So at this point, it seems there is no way to get Ubuntu running natively on the iPad. Not even the iPad 1 has had it's bootloader fully cracked yet by the iDroid team.
There are many other ways to get Ubuntu look and feel like it's running on your iPad, but running natively on the iPad will probably never happen.
Run Ubuntu on a headless server (or just any computer) and use a VNC app to access it.
Same as above, but instead of using VNC, you can use this app to natively run an X Server on your iPad.
Both of these require an internet connection to some Ubuntu computer.
I'm sorry to say it's just not possible to run Ubuntu directly on your iPad offline. The advantage here, though, is that you don't need to jailbreak your iPad for either of these methods, and it's completely legal and your warranty will be safe.
Plus, you can have your main Ubuntu Desktop (if you use a Desktop) run two X Servers - one for the iPad, and one for your normal desktop use. That way, all of your files would be in the same location and it would appear as if you were on your desktop (you actually would be), but you would be able to use both simultaneously.
If you really want a tablet that runs Ubuntu, buy a Nexus 7 or 10 - there's plenty of documentation to get Ubuntu running on those.
While installing Ubuntu on an iPad would be awesome, you need to really tinker with the iPad and open up the kernel.
This could possibly void any warranty attached to the device.
Since it is not possible to install Ubuntu on an IPad, the advice is to leave IOS 4 on your iPad and Ubuntu on your PC/Laptop.