I got Emma a 12 inch iBook for a birthday/Ordination present. To make it more enjoyable, I set it up with another 512meg of memory, and an Airport Extreme network card, so she can use it anywhere in the house. I also got a refurbed Airport Extreme base station (the one w/out the modem), and connected that to our Cable Modem through our existing home router. With all of this, I loaded Mac Stumbler on the notebook, logged in and got a solid 69 or 70 units (?) at my desk next to the base station.
This also has the benefit of raising the signal at the Airport Express downstairs that feeds the stereo – so now the iTunes feed from my old powerMac is rocksolid downstairs.