Google Maps mashup WhatsOpen pinpoints local businesses just like any other local search, then goes one step further by indicating which stores are currently open and which aren’t. It’s a simple concept, but if you’re actually using local search to find somewhere to grab a cup of coffee or get something to eat, it’s a really useful idea. Currently the search needs a little refining, and the public beta is California only (sign up for the full beta for US, EU, and China support), but this is one feature I’d kill to see integrated into Google Maps proper.