As reported in the firmware section, I have successfully booted and run Tinycore Linux 2.11 from a pen drive and, more recently, Tinycore Linux 3.6 and 4.0.
As the t5730 has conventional hardware and BIOS I would not anticipate any problems in running almost any Linux distribution.
Update: November 2011. I had an email from Ralph W Siegler about USB booting:
Before today I could not get my HP T5730 to boot either Linux or any BSD from large 40, 60 or 64GB usb connected drives or sticks, it only seemed to like very small sticks of less than 1GB. This is very unlike my T5700.
I had idea to install grub bootloader in a small FAT partition on big 60GB usb attached 2.5" disk with FreeDOS on it. That is the ticket to allowing OpenBSD, FreeBSD, or Linux to be installed in other partitions and booted on the rest of the drive.
I used grub 0.97 on a desktop computer, made c:\boot\grub directory, and put the three grub boot files from Linux boot disk in there: stage1, stage2 and fat_stage_1_5 and then made a file (c:\boot\grub\flag.txt) to help locate that directory while in grub. I then rebooted the desktop computer with FreeDOS disk still attached (but not *from* that disk). Then I started grub, and at grub prompt typed:
to get its disk/partition name from grub's point of view, which in my case was hd(1,0). I then did:root hd(1,0) setup (hd1) quit
Then made a menu.lst file in c:\boot\grub, keeping in mind hard drive on thin client would be hd0default=1 timeout=5 title FreeDOS root (hd0,0) chainloader +1 title OpenBSD root (hd0,1) chainloader +1
This can be adapted to any open source OS, works with Ubuntu, Debian, FreeBSD, OpenBSD.
Some time ago I wrote a few words about installing grub/Linux onto a Compact Flash card but using another system rather than the target hardware. This shows you how to tell grub that, though you may be installing it on (say) sd2, in fact it will actually be on hd0 when you use it for real.
Any comments? email me. Last update November 2011