I just released version 1.1.2 of my Masked Input Plugin for jQuery. Felix Geisendörfer helped me mash out a few things with this release. He fixed the bug for Mac/Firefox with the backspace key and got me to open up the caret positioning functions. Thanks Felix!
Here are the changes for this release * Fixed a bug in Mac Firefox with backspacing. * Fixed a bug where delete at end of mask produced an extra placeholder character. * Exposed the caret positioning and retrieval methods as a jQuery function extension. You can now call $().caret() to get a caret position and $().caret(start [,end]) to set a caret position. Please go check out the latest version at http://digitalbush.com/projects/masked-input-plugin