can i use an Ubuntu 11.10 for netboot over PXE? im aware of the LTSP and other similar proyects, but i dont find information using ubuntu 11.10 (the latest)
Your question is quite evasive .... I hope I'll answer you correctly.
You can do netboot with PXE in almost any version of Linux (if not all of them). This method is quite old and is assured with the TFTP server.
The TFTP server (with help of the dhcp server) is what is sending the PXE stack to your machines. However this is only the first step for any netboot method.
TFTP is compatible with any machines but his side effect is to be quite limited. In all modern method it is used to send only the requirements for booting with another protocol (ISCSI, NFS, ...).
To be specific to ubuntu 11.10 you'll find some help to build a TFTP server here : https://help.ubuntu.com/11.10/installation-guide/i386/install-tftp.html
Here you'll find a generic PXE stack : http://etherboot.org/wiki/start
However you'll just have the booting step ..... witch is incomplete : booting what ? A Live CD, A linux, ...
If it's help with LTSP you need (witch is more complete, it covers the pxe part and after). This page will have almost all his help for 11.10 : https://help.ubuntu.com/community/UbuntuLTSP
The short answer is basically yes (of course) :)
Without more information it's hard to give a better answer (do you want Ubuntu to be the PXE server? the clients? Ubuntu can trivially do both), but you probably want to start with something like this:
I don't think it's really worth copying an entire "how to set up a TFTP server" here, the Internet is teeming with examples already.
I don't have a definitive answer, but I can say that my school uses Ubuntu (I think 10.04 LTS) for netboot to thin clients.