I wanted to try Ubuntu one to see if it's better than dropbox. So try to create an account. I Used the built in software in 11.04.
it worked fine until I filled my email address. I got the red warning sign saying it was something wrong, but I checked they were the same and everything else was correct. I then tried to use the Ubuntu-one site but that failed as well since the "anti-robot-thing" never showed up!
I have an Asus 1201n with Ubuntu 11.04 64-bit desktop.