I think if it was possible to just flash the image via the N900 that in itself would be considered cool. I've jailbroken iphones without creating and patching images as their are ready-make firmwares.

Wait.... is there really no open source way to jailbreak lying around on the internet? As for spead, is PS jailbreaking really different from iOS jailbreaking? On that note, the practicality of jailbreaking anything from the N900 is the same as the advantage of a computer-like device in a tablet form factor. Portability; doing it on the fly for someone instead of with a laptop.

the greenpoisen jailbreak is open source, but a linux version has not been released yet while a mac and windows have, am trying to get hold of someone to ask for the source code.

If it is open source I don't think you have to ask. It'd be available in some code repository somewhere openly. I'm fiddling with something entirely unrelated right now (a power-button-menu rotation lock button instead of the status menu one ; only cssu relevant - because no one else was bothering to make one) but if you can't figure it out within a couple of hours I'll try to get around to looking up where the source code is for you.

theres other source code lying about, but it needs someone who knows what there doing with the actual jailbreak to make it work rather than a port, I'll have to look at it tomorrow, its getting late and I've got college, I appreciate the help though.

The greenpoison payloads are open-source, you'll probably just need to have the N900 go into hostmode, send commands and images, then send more commands. The problem, however, is the timing. If you cant send a certain command (too lazy to look up all of this on the iDevice wikee) fast enough, you get stuck on the white screen (pwned dfu).

And yeah, about the IPSWs (redsn0w approach), if you want to JB resonably quick, you have to prepare them from a computer.