I am using an SSD for my boot disk, OS, applications, & database.
My home directory is on a pair of raid 0 rotating media drives along with the MythTV recording directory.
The SSD makes booting linux and loading applications much faster. It also eliminates the disk contention that was screwing up recordings when myth was trying to do something with its database while recording TV.
I had some issues with the SSD in 11.10. It would boot so fast that some race conditions that did not show up with rotating media caused boot failures with an SSD. This seems to have been fixed in 12.04.