git add --patch file.name

I would highly recommend reading http://tomayko.com/writings/the-thing-about-git, it highlights yet another awesome feature of git. Git lets you do your work how you do it, instead of how the SCM says you should. Here is a great example. I have a hopelessly muddled set of changes in file_the_other.txt. The changes are for two (or more) different purposes, and I need to only push a portion of it. Enter `git add --patch`. I can go through each diff element and select to put it in the queue (the Index) for what will be committed.

$ git add --patch file_the_other.txt 
diff --git a/file_the_other.txt b/file_the_other.txt
index 2120d21..e3aa90d 100644
--- a/file_the_other.txt
+++ b/file_the_other.txt
@@ -1,3 +1,6 @@
+World is here
 A file like another file, but with different content.
 
-There is even more content here.
\ No newline at end of file
+There is even more content here.
+
+Hello World
\ No newline at end of file
Stage this hunk [y/n/a/d/s/?]?