When I need a change on scenery, I go to the library to do prep for things like stats, encounters and things like that.
For NPC ideas, I go to a busy place like a coffee shop. Sometimes I just draw and take notes on the different people sitting, eating and having conversations. Other times talking to people can help me out with personality types and mannerisms for NPCs (as well as having the chance to meet someone new, of course!).
Nevertheless, I do like to get a change of venue some times. Starbucks are one of my favorite places, they got coffee, wi-fi and usually an open table if you hit the right one, sometimes even good music. Any coffee house would probably do.
As the title implies, this is directed to those among you who, like myself, suffer from untidy house syndrome (or, put differently, are slobs!). I'm not exagerating when I say there's not one clean flat surface in my home that's not covered in assorted detritus which I'm too lazy to put away... Besides, even if I do clear off a table it just gets filled up again in a matter of days, if not hours.