Have you ever told Paul Ginsparg that the software behind his arXiv.org is getting a bit old? Did you need to show him how the arXiv.org would look like with some of the new gadgets? Andy Stevens and folks at IOP can show you how such an archive looks like:
It has several small useful gadgets such as an RSS feed for each separate archive. You can now add hep-th to your Firefox toolbar, among other things.