Hard to find electronic adaptors - phihong.com

Travel a lot? Lose things like adaptors? Found this site the other day - phihong.com.
They've got some interesting adaptors. If you don't have a visit to Taiwan or Akihabara in your plans, this might be a good place to go.

And for regular cables like HDMI, monoprice.com looks to be a good bet. Never shopped there, but they have a great rating over at resellerratings.com.

Good luck in your search!