Great! Just finished working on the 4-bit thing myself!
Here's a wiki page i've started on LCDs.
http://www.arduino.cc/playground/Code/LCD
Perhaps you can add your code as an attachment there. Better still, if you find the 4-bit LCD library there acceptable, we can fold the two together.
Wish I'd had your work available 
At least after our efforts no newbies should be stuck on this stuff!
Adding a wiki page is as simple as accessing the page-to-be's URL with ?action=edit added to the end of the url. e.g.
http://www.arduino.cc/playground/Main/GlasspusherTestPage?action=edit
would create the page "GlasspusherTestPage" in group "Main".
You'll need to sign up for a contributor account, but that takes all of 10 seconds:
http://www.arduino.cc/playground/Main/Participate#requestaccess
Going to read your code over now, and see what glaring errors I've made in my ver of the library.
neill