Even the best of RIM's BlackBerrys will not appear as nice and expandable as an equivalently priced PDA like the HP iPaq. However, for staying within reach there is nothing better: The BlackBerry allows for true e-Presence as in "electronic", "everywhere" and "easy"!.
The effective keyboard combined with simple one-handed navigation and a decent screen makes it very attractive for e-mails, addresses, notes and tasks. With the latest system upgrade (3.8) it even includes the essential categories when synchronizing with your Outlook files.
Take a closer look at the BlackBerry gallery
Make no mistake: The BlackBerry is a keyboard-centric mail device, not a hybrid-pocket-media-gadget; there isn't tons of applications out there waiting to take your focus from the task at/in hand... As such the BlackBerry must often co-existing with a PDA, which require a little planning but isn't a technical problem. You have to decide what data resides where and under what circumstances does one repository update the other. Map it out and stick to it.
I'll read a book and surf the web on my PDA while listening to MP3s. But if I could have only one device, I'd take the BlackBerry any day! It is so good at the limited scope that it far outweighs what you miss in flexibility!
The BlackBerry may bring your e-Presence one step closer.