ryck,
Quote:
This is an interesting idea and something I'd like to do for my daughters' laptops. Although I run Snow Leopard they're both 10.5.8 . . . .
(snip)
3. At the point my daughters decide to move to Leopard, is the flash drive updatable?
(snip)
. . . their machines are Powerbooks . . . .
A PowerBook is a PowerPC and cannot run Mac OS X 10.6.x which requires an Intel Mac.

There seems to be some discrepancy between this Apple Knowledge Base article, Starting from an external USB storage device (Intel-based Macs), and this Mac OS X Hint, Easily boot from USB 2.0 drives on PowerPC Macs.

I do not have a PowerBook with USB 2.0 ports so I am not able to test booting it from a USB external drive.

Back up everything you can't afford to lose: documents, mail, movies, music, photos, and other data and settings.