hehe, you're probably right Steve. The closest I saw before that was those water feature balls, pretty similar but a lot heavier with a pump etc - not easy to carry around!
Yeah, christmas baubles are another good one too, again the bigger the better.(and without glitter on )
The first thing I used was actually the back of a deep silver ladle. More or less spherical and a bit dented but it created the first 2 HDR images I did, available for download at:
https://www.flash-fx.net/3D/ (scroll down a bit till you see the hdr screengrabs and you can download them from the links)