Well it's all over, for now. The rain held off and although we played under a green gazebo (which made us look a bit like the Incredible Hulk but without the muscles) it actually went really well.
We only played a short set of eight songs, four originals and four covers (all Kings of Leon) - total time about 35 mins but I'm taking the lack of missiles and booing as a postitive. Got some good feedback and the biggest applause was for one of the originals so that was nice. Made a couple of mistakes. Got distracted by my Wife and lost my timing but just stopped and jumped back in at an appropriate moment and the drummer managed to launch one of his sticks at me - luckily he had a spare set on his kit so it wasn't too noticable. Been told that I've got to develop a poker face as apparently you can tell by looking at me when things go wrong!
Overall a very succesfull day and we managed to pick up a couple of potential future gigs. I'll put some pics up when I get them off the camera and also post a couple of youtube links to the vids. Thanks again for all the comments.