I just discovered this feature. I wanted to share it for those who haven't come accross it yet. The problem I had with Palm Address Book is that some of my contacts have 3 or 4 email addresses (home, work, mobile, SMS, pager, etc). Since we only have 5 info items, I was running out of info items (home phone, work phone, mobile, leaves only two available for email addresses or fax or others).

What I discovered is that you can enter multiple emails in one email information item. You can separate them with "," commas. (You can also separate them with Ctrl+Enter (carriage return), but when you try to send an email from Palm Desktop, the email address will appear funny in your email address "To:" field.) So I find it best to use commas, then when you send an Email from Palm Desktop you can remove the email address you don't want (because all of the email addresses will show in the "To:" field).

The really cool thing is that when you "lookup" an email in SMS on the Treo, it shows the multiple email addresses you entered for one contact and lets you choose either of them!

This doesn't work with phone numbers though. You can enter them (multiple phone numbers separated by commas), but the Treo contacts list only shows one phone number. It cuts off when it sees a comma. And therefore you can't select the other phone numbers if you entered more than one.

Taking this a step further, I was looking into the Jibe program that lets you sync Windows Address Book (Outlook Express) with the Palm Address Book and Desktop. It doesn't appear the Jibe will convert these multiple addresses into separate addresses in Windows Address Book (WAB). I put a request in to their development team to see about doing this.