Syncing macbook to external hdd

I have an '08 BlackBook Running Snow Leopard and am wanting to know if there is a program or a way to use applescript/Automator to sync my laptop to an external at a keystroke/click? The entire thing wouldn't be necessary, the most important things: Pictures, Design projects and such. I do not like TimeMachine's setup. I have Carbon Copy Cloner but it takes a while to compare and backup. I'd like it to simply as possible sync any changes to the most vital folders to my HDD. If it helps, I have a 250gb in a sata case and in the mac is a 320gb. I do have an 400gb desktop as well. Overboard I know, but I've lost stuff before due to HDD failure and now play by better safe than sorry rules Thanks for any help.

I've been using and really like backupList+. It lets you select which folders you want to backup and gives you many options for timing, types of backups, etc. Here's a link to the developer's page Rob DuToit OSX Software