Sure have, My Mac Mini has one of these fitted and it works beautifully as a slot in replacement of the Hard Drive. (Same form Factor and no adaptors needed)

http://www.zheinossd.com/dfg6__92.html

128GB model in mine has plenty of space for MorphOS and a lot more besides!! Should you also need to replace the Optical drive at any stage (as I have has to) then this drive means you can use a laptop optical supadrive as the Zheino SSD can be switched from Slave to Master to accomodate a differently hardcoded optical drive.