We started to get into anal sex about two months ago (thanks in part to this website). And a few weekends ago, on our 3 month anniversary of all things, we stopped into a store selling all types of sex toys, and picked up a glass dildo about the same size as I am down there.
On a few occasions since then (usually Fridays or Saturday, and not every day since taking it all from behind takes more time than we sometimes have) we've soaked it in some warm water and have been experimenting with double penetration... It get's pretty wild, but she really seems to enjoy it.