You can use CUPS and other packages as described in http://www.dd-wrt.com/wiki/index.php/Optware
I changed my firmware to dd-wrt.. it seems faster, but I was wondering if anybody has gotten USB printing to work on it.. if not, I might have to go back to the old firmware because I need printing.
I do however, want some of the features on dd-wrt, such as MRTG to work.. so I'm hoping there's the best of both worlds somewhere...
You can use CUPS and other packages as described in http://www.dd-wrt.com/wiki/index.php/Optware
I tried all that was listed, still couldn't get it to print, so I went back to the old firmware.
I did notice that downloads from the internet were better with dd-wrt, but transfers between two computers on the same network, was much better with Oleg's firmware.
Oleg's firmware topped out at a whopping 98Mbits for box to box transfer:
(Server Side, Gentoo 2.6.x kernel + vsftpd)
(Client Side, XP box running LE_FTP passive)
dd-wrt topped out around 64Mbits.