I was toying with this idea mostly for a backup boot drive for my 2010 Mini. Since SDHC memory cards are so small, that's why they appeal for this use. I have 32GB ones that should work just fine since I'm now using 40GB SSD's for boot drives. My current boot requirement is only around 27GB with OSX, Home, all Applications, etc. Think what a nice compact size you could have for a boot drive. The question is can you boot to SDHC's. If you can boot to an USB stick, why not an SDHC? If it routinely works, then I could use both internal drives for lots of data storage. Hey, maybe that could replace SSD's for boot drives. Or maybe the transfer rate is too slow for SDHC's. Any ideas? Opinions?