If this is covered elsewhere, I apologize in advance, but I wasn't able to find it. I just ordered a Crucial M4 256 GB to add to my 27" 2011 iMac. I recently got one for my 13" MBP, and I was so blown away by the performance improvement, I just HAD to get one for my main machine too. Even though the installation is pretty damned scary I've built and rebuilt many PC's, but I have to admit that this SSD installation has me nervous. Probably because I've never torn down a $2k+ PC before. In any case, I plan to use the internal 1 TB drive for user home folders, and the SSD for everything else. I am not sure on how best to make this happen. The procedures I have in mind is this: PROCEDURE A 1. Make a backup of the system first 2. Copy the user folders to an external hard drive 3. Install the SSD. 4. Do a clean install of Lion on the SSD. 5. Erase the original drive and copy the user folders back onto it. 6. Create the user accounts and then change the home folder locations to the original drive. 7. Reboot and delete the home folders on the SSD. 8. Reinstall all of my applications. PROCEDURE B 1. Make a backup of the system first 2. Move media and user data to an external drive (mostly music and videos), and/or uninstall apps until I get below 256 GB on the original drive. 3. Back up again. 4. Install the SSD. 5. Use Time Machine to bring everything back to the SSD. 6. Erase the original drive, and move the home folders to the original drive. 7. Reboot, then move all my data back to my new home folders from the external. I'm leaning towards Procedure B, but I'd welcome any other suggestions.