Yep, I have a tendancy to sleepwalk and sleeptalk. Few things I've done over the years:
-Believed I was sleeping on the couch in the front room, went to climb over the back of the couch (lifted my leg up a couple of feet to accommodate what I thought was the seat back, but was just thin air) fell down and bust my lip on my bed. Then proceeded to walk into my sisters door and get blood all down it, unfortunately my mum had cleaned it up before I woke up after she put me back in bed (was only ~7yo at the time)
-Shouted at my girlfriends mum when on holiday, thinking it was my sister coming in our room (I had fallen asleep straight away and she was talking to the girlfriend) and told her I'd punch her if she didn't get out...then woke up and apologised to her as I realised what the hell I'd just done. Didn't live that one down for a while
-Shouted random things that have been taken in the wrong way, most noticeably "mam, stop it" - when camping and a gust of wind blew the tent violently and I got woken up, it was meant as in getting her to stop whatever was happening (not quite sure why I said it really) but my mates found it hilarious and claimed it was meant in another, err, 'wrong' way...
lol
-Believed I had been at a gig which I was going to in a weeks time, and that there were 5 people staying in my room. I panicked when my mate wasn't in bed next to me, and my other mates weren't on the floor or in my chair. I then went downstairs and looked under all the cushions in the front room (WTF?!) until I realised "hang on, what am I doing?"...then I went and drank a big bottle of milk (2 litres) and put the empty carton back in the fridge and went to bed.
There are plenty more, current girlfriend has had conversations with me in the middle of the night a fair few times which she always likes to remind me about.
It's often when I'm in places I'm not used to (camping, other mates houses, hotel etc) but there's no real pattern to it