Comment on TextExpander

I tried TextExpander and TypeIt4Me (which I actually purchased) and Typinator wipes the floor with them. It expands fast in all apps I've tried (unlike TypeIt4Me), it has lots of options as to expansion (i.e., per-abbreviation space options), and the full size interface is much more useable than the prefpanes of the other two. It also has nice per-app and per-abbreviation exclusion capabilities.

TextExpander is good, but more limited in my opinion (plus more expensive). Before you settle on this app, take a look at Typinator.