Steam Streaming
We're just dipping our toe into the following: A several years old gaming PC in the basement (i7=920, 6 GB, GTX280), running Steam under Ubuntu OS. It streams the Steam games over the LAN to any old non-gaming PC or laptop.
The goal is the physical convenience of a laptop, combined with the gaming performance of a huge tower.
We can't yet report on the results, but it's looking hopeful.