I've got an Ipaq 2210 and wouldn't like to be without it.
I have used it to connect to the internet but I wouldn't recommend it for that - far too restrictive compared to a PC.
So what do I use it for?
I can show people my digital photos (I can take the flash card out of my camera and plug it in my Ipaq).
Have several hours of mp3 music stored to listen to through earphones or through my car radio.
I can convert a dvd to fit on a flashcard if I want a film.
I can have several books on the flash card.
I can store notes, all my addresses and phone numbers.
All my passwords, credit card details etc are stored (encrypted of course).
I have a converter program that will convert currency, length, fluids, etc etc etc. & calculators.
I can record voice notes.
I can translate German and French to Engish.
I can use it to replace any number of remote controls.
I can make and use Word or Excel files.
I can play games of all descriptions (Scrabble is my favourite).
I'm sure I've missed out things but this is mainly what I use mine for.