"I'm planning on purchasing a new 2.5" external hard drive (Not 3.5" - Don't really like the power cords. Always have to set it up and 'take it apart' every time I use them.)"
I notice by your signature that you are using a white MacBook. Does this have only USB, or does it have firewire as well?
There's a potential problem here that you should be aware of when connecting portable drives to Macs with the intention to run them via "USB power only".
That is -- sometimes the Mac's USB port does not provide enough "bus power" to get the drive spinning up properly.
Sometimes it will work. Sometimes, it won't -- you may hear the portable drive start to "spin up" a little, then it will spin down, or won't mount on the desktop.
The reason for this is that most Macs (not all) provide a lower amount of USB bus power than do PC's. And different portable drives seem to require different amounts of power. Thus, "what works" one time may not work the _next time_.
This is a somewhat "murky issue" but you should be aware of it before you buy, so you can make an informed purchase.
One "workaround" is to use a "two-headed" USB cable, that kind of looks like a "Y". One end has a single USB connector (that end goes to the drive). The _other end_ has dual USB connectors, and you have to plug BOTH of them into two of the Mac's USB ports to obtain sufficient bus power to get the drive up and running. Even with this, no guarantee that it will work.
Of course, the other solution is to have a small external power supply that you can use with the USB drive. This eliminates the "bus power issue" and the drive should mount right up.
Having written all that, you should also be aware that if you have firewire, the port power problem is a non-issue. A small 2.5" firewire drive should mount right up.
But trying to get a small USB drive up and going with bus power only can sometimes present problems....
So make sure that whatever portable drive you decide on -- that it comes with an external power supply as well, just to be sure. You may need it, then again, you may not. Caveat emptor.