[te_chris]

I've been using sourcetree lately, really, really enjoying it - though line committing is pretty cool, I have apps hosted in places other than github though.

[shadowfiend]

Github for Mac actually works with any remote repository. The link to Github is superficial.

[etherealG]

sourcetree has line committing, when in commit/diff view drag on the lines you want and right click, you can commit only a few lines, even if they are only part of a hunk.