The Asus 4 port/wireless router (model no. WL-520GU) is available at ZipZoomFly.com for $49.99, but for today only (1/21/09) they have reduced the price down to $39.  This $10 mail in rebate offer drops the price further to $29.99 making this the lowest total price we could find on this router by around $15.  FREE shipping is include and sales tax applies for residents of California.
 

The Asus router has 802.11b/g wireless broadband routing capabilities and also has four ports for connecting other computers via Ethernet cables.  Features include EZSetup and bandwidth-on-demand that prioritizes bandwidth needs.  It is backed by a one year warranty on parts and labor from Asus.  Dimensions:  (H) 1.22" x (W) 4.59" x (D) 6.46" ; weight 9.24oz.