Vim Slime: A vim plugin to give you some slime. (Emacs)
tarnbarford.net
tarnbarford.net
You could also use slime in vim with a rube-goldberg-esque combination of eclim (http://http://eclim.org/) and CUSP (http://www.bitfauna.com/projects/cusp/cusp.htm).
http://emacswiki.org/emacs/ComintMode
SLIME is much more than just sending code. It's a full-fledged development environment with commands for inspecting variables, viewing threads, stepping, viewing backtraces, etc.
This seems more general though, and clearly has the biggest feature nailed.
After the most recent bug fixes it has gotten a lot faster, so make sure you get the latest version from https://bitbucket.org/kovisoft/slimv/ - version 0.9.5 on vim.org still has a bug that causes it too slow down.