In the past month, i've been pretty exclusively handheld-only. After getting my SP back from my manager, i played a lot of Wario Ware. My PSP is such a guilty pleasure. i've lost a lot of sleep since launch telling myself i'll just play one more game of Lumines. Earphones, even crappy one, improve the experience with PSP and Lumines especially so much. i'm tempted to play a game right now, but i've got a thousand things to do before going into work today.
Thing is, i don't play much outside of the house. A lot of it has to do with being in situations where i'd rather be doing something else, like reading, or as Drinky mentioned, being in a place where whipping out a game system isn't going to win you any points with management/your client/etc.