Has anyone ever been in a drill team? I've been helping out with a local one as I always enjoyed how it looks, but I need some inspiration for new patterns. They've been running the same set of five for the past five years and its rather uninspiring to the kids (and their horses).

No, for some reason I do not have the cordination for that type of workout which surprising me since as a child I did baton rather well. It must have something to do with age. Are you sure they will allow changes made?

The only drill team I have been on was a military drill team. What kind of drills do the kids and horses do exactly?

Our kids are all just learning as alot of them have moved up or just decided it wasn't fun anymore. So we're working on alot of the mechanics of a smooth pattern. Here's a couple youtube videos you can see of some much higher skilled groups:
UVM Drill Team
http://www.youtube.com/watch?v=oyaPr4MYjEM

OHSET Drill Team
http://www.youtube.com/watch?v=2Na_dGz4Sgg

Its very similar to regular marching drill team, but much harder as you can imagine since you're mounted and its not always possible to get matching horses like UVM has (since they breed their own Morgans, lol). It can come out pretty wonderfully when done right. And its up to the teams to create their drill patterns, so yes I can change it as much as I'd like.

I would imagine that perfection is not always possible too because you are trying to impose your will on the beastie underneath you. If it were just you that would be one thing, but I am sure there are some horses, some days, that just don't want to play ball.

Most horses that aren't willing to cooperate won't get past the preliminary stages of drill. Based on how close the horses go they have to be pretty unflappable to do well for the rider. They can't be prone to bucking, kicking, foul moods, or general crankiness. Just like other sports you would look for a mount that fits your needs instead of trying to just make your horse fit instead. Although it can be fun to try ;)