In reply to:
Perhaps try and look for a switchmode (it will be much smaller and lighter) rather than a linear reg version. Quite often they aren't even regulated and simply have a bridge rectifier and a large filter cap in them. Particularly cheap and nasty if you ask me
That will explain the size differential - I asked Mr. Radio Shack what the deal was, why his was so much 'bigger' than the one I had, and of course - he didn't have a clue.. and nor did I to be honest.. I figured AC/DC was AC/DC - I am now 'edumecated' thanks!