You could try pfsense, its a free linux standalone firewall. Its only 50 meg or so to download, but the whole computer can only be used as a router once u install it.
Im not sure if u can install it to a flash drive though, but just an old IDE HDD would do the trick nicely.
It may take a bit of learning to set it up, but it has a nice web interface, and the wiki has a lot of step by step basic setup guides, complete with screenshots and everything so it shouldn't prove to hard to get basic functionality from it.
http://www.overclock.net/networking-...wn-router.html
That is a nice guide by Digital Sonata which you could take a look at.
If you have any questions ill be glad to try and answer them, at the very least i hope this can give you some ideas for building your new router.
Im not sure if u can install it to a flash drive though, but just an old IDE HDD would do the trick nicely.
It may take a bit of learning to set it up, but it has a nice web interface, and the wiki has a lot of step by step basic setup guides, complete with screenshots and everything so it shouldn't prove to hard to get basic functionality from it.
http://www.overclock.net/networking-...wn-router.html
That is a nice guide by Digital Sonata which you could take a look at.
If you have any questions ill be glad to try and answer them, at the very least i hope this can give you some ideas for building your new router.