Mac mail migration

I've been thinking more about how I am going to communicate over e-mail once I end up with multiple Macs in my life. As a PC guy, I'm currently using a Blackberry 8700c combined with Nelson Email Organizer on my Thinkpad T60p, with Google's gmail providing domain mail hosting, archiving, and web access. Although NEO is the best e-mail client I've ever used, it doesn't support any sort of synchronized mail solution. In fact, NEO doesn't even use IMAP the way it was intended to be used, so during times when I am away from my networked Thinkpad, I am effectively communicating by using another copy of my incoming mail. I bcc: sent mail all over the place so it ends up in NEO regardless of where I send it from, but it isn't the best solution. No organization is possible from anonymous web terminals, nor from my trusty Blackberry, and I have to file incoming e-mail again once I return to my notebook. Luckily, archiving a message through NEO is accomplished through a single keystroke.

NEO also combines multiple e-mail addresses into a single "correspondent." Even though Mac Mail has good search capabilities (I hear), if a friend has an e-mail address without full name specified, it may be hard to find that e-mail later on. I hate explicit mail organization, and would much rather be able to tag e-mails with categories and associate unknown e-mail addresses to correspondents and bulk mail folders (subscriptions) as they come in for the first time. After that, the database tracks everything and I only have to make mail "not active" for it to go away from the inbox. I hope Mail can do something like that, but early investigation is proving to be disappointing.

My Mac Pro is supposed to arrive next week, but I won't be switching my e-mail usage over to the Mac until I (eventually) get a Macbook Pro, which won't happen until Merom updates. At that point, I'll need some sort of email solution that supports two Macs, web access, and a Blackberry. Alex has written about this problem a lot, and I look forward to seeing his luck with Single-User Zimbra Hosting, should he decide to go that way

.Mac Accounts

Can someone comment on the effectiveness of .Mac synchronization across multiple machines? I would like to have my address book, calendar, notes, and some e-mail sync'ed across notebook and desktop machines.

I assume PocketMac for Blackberry works well enough that I can sync over contacts, calendar, and notes? If so, changes on my Blackberry would get sync'ed through to my (future) Macbook, which would then sync over to the desktop and web via .Mac, right? I'd only have to fire up Parallels to sync over eBooks.

My e-mail situation is also a bit complicated. Let's say I have 2 e-mail address I want sync'ed across multiple machines and to the web, and 2 more that I only want to check (via POP) from a single machine. Can I set up a .Mac account with multiple "accounts" that let me reply from different e-mail addresses, or can .Mac sync simply bypass .Mac e-mail accounts altogether and sync arbitrary folders/accounts from within Mail? How can I only sync mail coming in from 2 e-mail addresses while leaving mail from the other 2 alone?

And finally, there is still no solution to use a Blackberry as a modem on Mac OS X. I'm going to try taking a Cingular Blackberry's SIM card out, putting it into a normal, Bluetooth-enabled GSM phone, and using it as a Bluetooth modem. Haven't read anything conclusive about whether a SIM card set up as a Cingular voice + Blackberry account will work for data in a non-Blackberry phone.