Good stuff, I could imagine the cave being quite difficult, did you have a tripod with you?
And you manged to go and bag yourself a 10-20?
Put the star photos into the photo pool for this group on flickr http://www.flickr.com/groups/astrometry/ it'll try and identify what your actually looking at, didn't have loads of luck with the ones I posted but still worth a try.
Will do. I certainly want to give image stacking for astrophotography another go, I just need to find an idiots guide, as it's all either really basic "you need to use bulb mode" or fairly hardcore technical stuff, nothing inbetween...
The cave photos were all hand held, with only a couple of exceptions I used the 24-105mm f4 L at quite high iso's but with about 1 stop of negative exposure compensation. A couple I used the sigma for, but these were resting on the rocks.