Useful MacVim Script
A wonderful little script I use on a daily basis is the MacVim shortcut below.
#!/bin/bash
if [ $# == 0 ]; then
  mvim
else
  mvim --servername $(basename $(pwd)) \
       --remote-tab-silent "$@" 1>/dev/null 2>&1
fi
I have this saved as v in my ~/bin directory, and here's how it works:
~/code/tsaleh/tammer-saleh$ v Gemfile
Opens Gemfile in a new macvim window:

~/code/tsaleh/tammer-saleh$ v config.ru 
Opens config.ru in a tab in that same window, since we're still in the tammer_saleh directory:

~/code/tsaleh/tammer-saleh$ cd ~/bin
~/bin$ v git-fml
Opens git-fml in a new macvim window, since we're in the ~/bin directory:

The magic is in the pwd call, which names the main window the same as your current directory.  The result is a natural flow of tabs being grouped by the project you're working on, and it works quite nicely.