After playing around with vanitygen and spending a while looking for "available" vanity addresses by searching blockchain.info I discovered that already a very large number of plain english words have single tx's with a 0.00000001 BTC balance.
To get a good idea of what I'm referring to take a look at the following tx:http://blockchain.info/tx-index/1009186/4e7b84a7ee19b7ea9f2d69fcb2734fb096cb012b413f8897b4f42871b225faba
So it seems to me that someone went rather gung ho with vanitygen to try and own all the simple "firstbit" addresses they can possibly get. But what really can you do with them?
(maybe I can expect to see small amounts appearing in my wallet from these addresses after this post)