Provided I can ever get myself (i.e., my wardrobe, my house, my life!) sorted out, I might be interested in a swapsie sort of thing.
I have stuff ranging from probably US 16/18 (UK 18/20?) up to UK 24-ish or so...refer back to my sorting myself out comment. I tend to keep a range of sizes around because I've gone up & down the scales over the last few years, but I buy stuff that I don't seem to get around to wearing, or I got it & then changed my mind but didn't get around to returning, and things like that.
Interested to see what CB puts up - especially as regarding evening/party clothes with reference to my latest 'dress me' thread on Girl Talk for a couple events I have coming up.
Right now I'm about UK 24 on bottom, and UK 20/22 (depending on the garment) on top.