A while ago, I replaced my 802.11g router with an 802.11n model. Much as I love the faster performance and better range, it saddens me that the old router is collecting dust on a shelf. (Yes, I'm easily saddened.)
To avoid consigning your own router to the same fate, consider an inexpensive upgrade instead of a pricey replacement. Newegg has the Trendnet Easy-N-Upgrader TEW-637AP for just $24.99 shipped.
Designed to piggyback on an existing router, the Easy-N-Upgrader bumps your network's Wi-Fi performance to Draft-N levels (up to 12 times faster than 802.11g, according to Trendnet). It also promises better range, meaning that it may help overcome Wi-Fi "dead spots" in your house.
CNET hasn't covered the Easy-N-Upgrader, but you'll definitely want to read Maximum PC's review. It's quite positive overall (as are the user reviews on Newegg), citing mediocre range as the only real shortcoming.
These are new units, not refurbs, and you don't have to deal with any rebates. If you've been pining for 802.11n performance but didn't want to spend upwards of $100 or more on a new router, this looks to be a terrific solution.