Wireless file transfer speed question

Greets, all.

Could anyone here tell me if it is normal to see slow performance for
wireless file transfer from PC to PC via Windows workgroup?

All my machines run XP SP1 and have stable, speedy access to my cable
internet. When transferring files from desktop to desktop using wired
100mb/s, speed is fairly close to the actual max rate of my hard drives - a
700mb file takes about 3 1/2 min. to copy. However, when transferring from
wired desktop to wireless laptop (or desktop), speed is roughly 10 times
slower.

My equipment:
Linksys BEFSR41 router hitched to cable modem
Netgear WGR614 wireless G router attached as WAP (DHCP disabled)
Netgear WG111 USB G adapter
2 desktops connected by wire to Linksys router (100mb/s)
1 laptop connected by USB G adapter

I have no problems browsing my workgroup LAN as far as shared files, folders
and printers go. But when I need to copy a big file, I find that it is
painfully slow to do so over the wireless portion, and usually just patch
the laptop in via my knotted up 100-foot-long CAT5 cable.

Any way to get faster speeds, considering that my 54mb/s connection is
stable and strong?

Thanks.

Steve