I have that exact setup right, and it does work. They are both 802.11b (or whatever the standard is). When you boot up the laptop or bring it out of sleep mode, sometimes it takes up to 5 minutes to establish a connection. Also, the max transfer rate I get is 18 KB/sec. This is with the Powerbook in the same room as the linksys. I may have something configured incorrectly, but there really isn'y that masny settings to tinker with.
I researched it some, and the only thing i found was that the Titanium in the Powerbook isn't the best thing for wireless, but this has nothing to do with the linksys end of it.
You can PM me if you want more details.