TIP: Use your old PC as a print server! Don't throw it out just yet. :)   Many of my friends and clients have switched to Mac with the new lightweight sturdy unibody Macbook Pros but have found that part of the fun of having a laptop gets lost because they can't print wirelessly to their usb-only printer. So for Mac users, here's how.  You can read the full oarticle here:

http://macs.about.com/od/macwindows/ss/sharewinprinter.htm

The short version is:

1. Change your PC Workgroup affiliation to "Workgroup" (then skip creating a new location in the instructions)
2. Enable printer sharing for your usb printer in Windows
3. In the Add Printer dialog boxes on the Mac, look for the Windows Tab, and add the printer you see there.

Note that the link above recommends making the printer model "Generic Postscript", but you'll get better results on the Mac if you first connect the USB printer to the Mac and install the Mac drivers from the disk that came with the printer, or using the most current Mac driver from the printer web site.  And if you can't do that, also try to find the printer model in the Mac list of printers by choosing "other" as the driver option.  If that's confusing, the generic driver will probably work.

** As most PC users already know, to print from a PC laptop wireless to a usb printer connected to another PC, you simply use the standard built-in printer sharing- you just make sure that the printer is shared.