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.

As far as I can tell, Butler does all that TextExpander does -- as a bonus to its amazing app launcher/navigation/clipboard organizer uses. And its freeware/donationware. Go with Butler.

I just switching from Windows and was a huge fan of the fabulous (and free) AutoHotKey. TextExpander lacks most of the features of AutoHotKey but the really irritating part is that so far it won't even do text expansion properly. I type my hotstring and nothing happens. I backspace and try again, still nothing. I hit backspace and try again, ahh, now it works, but I could have typed it myself faster. If it starts working I may pay for it as it's a feature I really like. For what it does though it should be in the $10-15 range. If develops the full feature set of AutoHotKey then it'll be worth $30 or $40.

Fantastic Product which is getting a lot of hate on here from cheap cats who obviously don't use it properly or enough for it to be worthy of $30.

I made my money back on this app after a week of using it. If you code regularly - it is damn near essential for shaving off a LOT of tedium.

Love the product - great support - regularly updated.

In defense of some of the negative comments here...

I have saved tons of time using this app. It does an AWESOME job of helping me set keystroke commands for VERY simple "i don't wanna have to think about this" tasks, and then some.

A few examples: Typing...

ttime = the current time [2:31 PM]
dmdy = day - month day, year [Saturday - October 27, 2007]

I've also got long blocks of boiler plate text tucked away in there, as well as email addresses that I enter often. It would suck top have manually enter them when I can just set a shorten version of them up in TextExpander and save time, and reduce the chance of error.

Not to mention, the interface and functionality was just updated with the latest version (2.0.2) making it an even better app!

I have nothing but great things to say about TextExpander, and I love the time that it's saved me.

TextExpander 1.4.2 has a little bug: it breaks the shortcut that hides/shows the Dock (command-option-d), even if the shortcut is changed to something else.
Instead of toggling between hiding and showing the Dock, the Dock is hidden only when the keyboard shortcut is pressed and comes back immediately when the keys are released.

@arne: Exactly. 30$ is ridiculous.

Would have paid $10 for it, will not pay $30.

anyone know where they can find the free version?

Still holding on to the free Textpander -- the good old days. Works great!