Hi Roger,
There's a few voicemails on my cell phone that I would like to save to my PB,
OK. How about this:
You download and install little free (simple to use) app. from Versiontracker called
Audio Recorder 2.2. This will allow you to record simple audio from your PB's internal mic.
Then, you play back your cell phone voice mails one by one, each time placing the speaker of your cell phone near the internal mic of your PB (I think it's under the left speaker grille, but check your manual to make sure) and you use Audio Recorder 2.2 to record the voice messages to your PB's hard drive in the sound file format of your choice.
I'm certain there are other (probably more elegant) ways to accomplish what you want done, but I'm just as sure that the above will get you where you need to be.
Good luck.
JDee