damagereport

Reports duration of combat, damage dealt and dps to the frame of your choice when you exit combat. IT should be pretty lightweight compared to most damage meters since it makes use of statistics instead of combat log events.

By default this reports to UIErrorsFrame, that can be changed with this:

where frame can be any frame with an AddMessage method.

Here's a few frames you may use:
UIErrorsFrame,
ChatFrame1,
ChatFrame2,
ChatFrame3
These might also work:
noticeFrame,
RaidWarningFrame,
RaidBossEmoteFrame

/run dmgrprtsv="ChatFrame1" for example.

There's a git repository hosted over at github, feel free to contribute, or submit bug reports and feature requests.