Pretty Git branch graphs


I've seen some books and articles have some really pretty looking graphs of Git branches and commits. How can I make high-quality printable images of Git history?


Update: I've posted an improved version of this answer to the Visualizing branch topology in Git question, since it's far more appropriate there. Leaving this answer for historical (& rep, I'll admit) reasons, though I'm really tempted to just delete it.

My two cents: I have two aliases I normally throw in my ~/.gitconfig file:

lg1 = log --graph --abbrev-commit --decorate --format=format:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(auto)%d%C(reset)' --all
lg2 = log --graph --abbrev-commit --decorate --format=format:'%C(bold blue)%h%C(reset) - %C(bold cyan)%aD%C(reset) %C(bold green)(%ar)%C(reset)%C(auto)%d%C(reset)%n''          %C(white)%s%C(reset) %C(dim white)- %an%C(reset)'
lg = lg1

git lg/git lg1 looks like this: git lg1

and git lg2 looks like this: git lg2

(Note: There now exists much more applicable answers to this question, such as fracz's, Jubobs', or Harry Lee's!)

go get results in 'terminal prompts disabled' error for github private repo

Edit the root commit in Git?