The script is quite a hack -- it checks every tenth of a second to see if the currently active tab isn't zoomed in. If it's not zoomed in, the script activates the corresponding keyboard shortcuts to zoom the page. You can edit the script to change how often the zoom-check should be made, and what level of zoom should be made. With a delay of 100ms, the scripts gobbles 1% of the CPU time on my system. One idea is to make an application from the script, and launch that instead of launching the script directly from the AppleScript Editor. Any suggestions for improvement are welcome!
[robg adds: I tested this in 10.6.2 on a MacBook Pro, and the script used about 5% of the CPU. It did, however, work as described.]

