File List is another Mac app that I couldn’t live without. When I put together music and sound effects collections I receive huge amounts of data from composers all of the world. They send their files with all kinds of bizarre naming conventions and I used to go through file by file and change every single title by hand.
It finally got so out of hand that I did a quick search and found File List (Name Mangler now?) and have been using almost everyday since I downloaded it.
File List batch renames files on your Mac according to criteria you set up. Rename files using sequential numbers, prefixes, or suffixes, or change to upper or lower case. File List supports advanced file naming specs that let you use conditional statements too.
You can download it here
http://www.manytricks.com/namemangler/
and start renaming files.

This tip I got from the book Upgrade Your Life really helped me out on a recent trip to Mallorca. I took my beat up old macbook just to minimally keep up with customers questions and orders while visiting the Spanish island for 9 days.

Just before we left for the airport I was rebooting and my Macbook completely crashed and needed its system reinstalled. I took the install discs with me and when we got to our chateau on the coastal mountainside I reinstalled OS X and then was left with nothing but the default installed software.

I remembered that I had just signed up for and synched with Xmarks just before I left and gave it a go with a new download of Firefox on my laptop. It worked beautifully and my laptop had everything I needed to get to all my bookmarks and also remembered passwords which would have taken me forever to figure out.
Needless to say I’m a total Xmarks fan now.
http://www.xmarks.com/

(this is good for PCs as well of course)