Here’s a tip I just read over at the brilliant Hawk Wings blog.

You can copy a person's email address in Mail by clicking on their name and choosing "Copy Address from the contextual menu. For some reason, Snow Leopard will copy the email address in angle brackets, instead of just the address. So when pasting you will get <matt@macosxtips.co.uk> instead of just matt@macosxtips.co.uk.

This might be useful for some people, but I really prefer the previous behaviour. To change the behaviour of Mail back to the old way without angle brackets, just use the following Terminal command:

defaults write com.apple.mail AddressesIncludeNameOnPasteboard -bool NO

To run it, open up Terminal located in Applications/Utilities. Paste in the line, then hit return. Quit Mail if it is open, and now when you next open it you won't get any angle brackets when copying addresses.