"I'm looking to buy one down the road, to backup my stuff, just in case. Looking at something that isn't overly expensive.
If the time capsule wasn't 300 dollars I would get that."
Don't waste your money on a Time Capsule, they're not worth it and have a record of failures.
Here's a low-cost solution that will get you going quickly and cheaply:
Get one of these (various items shown):
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=usb+sata+dock&x=0&y=0
I've seen USB/SATA docks go for under $15 by watching dealmac.com.
The one I use is:
http://www.amazon.com/Syba-Connecla...?ie=UTF8&s=electronics&qid=1253062702&sr=1-22
Then, pick up a "bare drive" of your choice from the vendor of your choice.
Again, dealmac.com is a good place to keep an eye on sales.
Download CarbonCopyCloner from here:
http://www.bombich.com/
You can use CCC to "dupe" your internal drive to the external. This will create a bootable clone, as close to an exact copy of your internal as you can get. You can also use CCC to do "incremental" backups so that the backup drive is maintained in the same state as is the internal.
The best thing about having a USA/SATA dock around is that you can put another drive into it whenever you want, etc. Very flexible and very useful.