Well, that was interesting. I tried selecting the hard drive as mentioned in the previous post to see if that might speed things along. I don't know if my new hard drive was already selected (I couldn't really tell) so I selected it, locked it, and restarted.
At first I thought it sped things up a bit but I wasn't sure so I shut down for a minute and started up again. And, start-up was definitely a bit faster. However, I just turned my MBP back on after being shut down for a little over an hour and start-up was considerably slower than it has ever been.
The conclusion. My problem, whatever it is, seems to be kind of periodic. I don't know how this can be exactly, but since I upgraded to Leopard (from Tiger) after the drive upgrade I think the OS may be the culprit.