Maximizing Speed within a Home Network with a WRT54G

I recently installed the Windows 7 RC on both my laptop and my desktop, and the new “Homegroup” feature really made it easy to share files between PC’s. Both my PC’s are connected wirelessly to my Linksys WRT54G, so I know I won’t get the 100mbps that wired PC’s get. However, I know Wireless G can reach up to 54mpbs (In a perfect world), but I’m only reaching speeds of like 13 and 14 megabits per second. Both my laptop and my desktop are in the same room as the router and have full bar connections, so is there any way speed it up? I really don’t want to connect both of them to the router with wires because it would just look really with the way my room is set up.

Any help is greatly appreciated.