Some of mine not already seen:

    alias mirror='wget -m -r -np -p -k -E'
    alias g_short_hash='git rev-parse --short --verify HEAD'
    alias g_head_branch='echo "`git symbolic-ref HEAD 2> /dev/null | cut -b 12-`"'
    alias g_branch_w_hash='echo "`git symbolic-ref HEAD 2> /dev/null | cut -b 12-`-`git log --pretty=format:\"%h\" -1`"'

On OS X:

    alias sleepnow="pmset sleepnow"
    alias netstat_tanp="lsof -Pnl +M -i4 -i6"