iPhone 4 cracked and will not slide over for password.
Man...that's rough.

If you have been backing up to iTunes or iCloud, your stuff should be there.  You are backing up, right?

There are a couple more options you can try before you take your iphone in for repair to get at your data:


Bluetooth Keyboard - just connect and enter your pin
Voice Over - triple tap the home button and "say" your pin


Both of those must have been previously set up.  If you didn't set them up, they aren't going to work.  

One more you may want to try...

If either of those two methods are unavailable, try PhoneView which will allow you to get access to everything on your phone via your Mac.  It costs about $30, but that may be cheap considering how valuable your data is.

Finally, if all else fails, you will have to have the digitizer replaced.  Maybe a local repair shop can hook up a digitizer temporarily so you can back up your data, but that would be a long shot.