Version 5.2 of Google Maps for Android adds two new features: the ability to post your reviews of restaurants etc straight to Twitter (please refrain from spamming your followers, people), but now you can also ask friends to check-in with you using Latitude, so you know when they've arrived somewhere.

Say you're in a really crowded bar at the back, and you won't see them walk through the door. Requesting them to "ping" you instead of calling or texting will save them time and money (if they don't already get free texts, that is.) [Google Blog via BGR]