I did. Totally unplanned but I'm really glad I did.
I had to be a bit in and out of the water (wasn't progressing quickly enough and there was mention of hooking me up to the drip, so I got out to try and speed things up; then at the end DD's heart rate dropped so I had to get out again and didn't actually give birth in the water). But when I was in there it was so much more bearable than on dry land.
Things to consider: it limits your pain relief options. You can only have gas and air. (But, if things get too much, you can always leave the water and go for something stronger.)
You might have to get out near the end and it might be too late for any other pain relief options.
It's difficult to reach for things you might need - drinks, sweets etc - so make sure birth partner is fully versed on getting things to you ASAP. Get a hand signal if you need to!
It is lovely (well, as lovely as can be when you're in labour) to be swishing about in the water. I had incredibly bad back pain and the water soothed it so much. I was on the verge of tears when I was out of the water but coped much better in.
Oh, and plan better than I did; take swimwear. I was naked the whole time 
I'm planning to have a home birth if I have another but I'd still hire a birthing pool.