They're rather inexpensive, so why not? However, I'm also trying to decide what capacity and type to buy. I currently use a Samsung Galaxy s2 4G on tmobil. AFAIK, the benefits of a class 10 card isn't really going to make for the extra cost. 16GB is pretty good price, but don't think 32GB will be worth it. All I want to do is..... --fast and easy way to transfer media files on the go, or directly on the phone --keep a few scant few files (e.g. Office documents) and media around (the bulk of my music is on my classic Ipod anyways) --backup some crucial data perhaps (although my contacts list already run off the SIM card, but changes to UI and menu options perhaps) --backup game saves (dunno if it's possible to do that. The only thing I have for now are Angry Birds Seasons and Angry Birds Rio. Not a big deal, but I did sink alot of time into those. I'd hate to have to replay them from the beginning) What I won't be using it for.... --supplement storage space on phone I don't anticipate storing mounds of data and media on the phone nor cSD card Any other good uses I'm missing with an Android device and micro SD cards?