Running Lion (10.7) on a 2006 Macbook
I recently installed Apples new Lion (10.7) OS on my aging white Macbook from 2006. It has a massive 2Gb of RAM, with the awesome power of a 2.0Ghz Core2Duo CPU and GMA 950 graphics processor, along with a very speedy 5400rpm 250Gb hard drive (full specs). This thing was a speed damon in 2006, 5+ years ago now ! It just scrapes in on the minimum spec requirements for Lion, and I was pessimistic about how well it would run, given that Snow Leopard was less that fluid on the system. To my surprise the upgrade went quite well, and the system was running almost as well as SL was. I then did a clean instal of Lion (as my old SL install was bloated and over due a go clean). This resulted in a very useable laptop. Its not going to make an old Macbook suddenly crunch current benchmarks, but I can safely report that the minimum specs listed are more then sufficient to run Lion successfully.
UPDATE: As requested I have added some info/pics showing the memory usage during various settings. First is just iTunes, Word, Mail, Safari running. Second, I have a SD video file playing in VLC. And third is a HD720p YouTube video playing. The aging GPU in the Macbook struggles with the HD Flash files a bit. But that could also be because I am running an additional Dell Monitor off the laptop in extended mode, which would be pushing the GPU a fair bit by itself.