Nice touch Hil, but I really wish campaigns made more attention to deliverability issues and email standards. The standard for many of the most common email providers is to block images from ever showing up, so a lot of people don't realize what they're missing. For more on this problem, check out this small study by M&R (PDF).

These email gimmicks are in the end of a waste of time and effort by the campaigns. To use images directly in email is an invitation to have many of your supporters completely miss a key component of your messages.

This is a common technique from the UK. There political parties (originally the Lib Dems but now all of them) do letters at key times (usually eve of the election) that are genuinely handwritten on the envelope (not an impossible task with some clerical volunteers, a bit of targeting and short addresses / hand delivery) but have a printed blue handwriting font on the inside.