Anywho, Subway Art is certainly trendy right now. It's inspired by the vintage signs found in subway stations with the different routes/trains listed. Something a little like this:
These are reprints that are being sold be Restoration Hardware. I love the look of them; clean, simple, straight, and not much extra space (or "white" space).
If you check out their selection, you'll see these reproductions are a tad bit spendy. So, crafty people out there in blogland are creating their own versions of subway art, and some of them are quite nice, in my opinion. This type of art is being adapted to many different things: family rules, wedding invites, holidays, birth announcements, etc. Below are a few favorites I've seen out there...
A birth announcement I created (of course I had to throw in something of my own!)