I don't carry more than my phone and perhaps my iPod in a daily basis, but when I travel it's with a Keen messenger bag. I like it a lot, with the only problem being that it does not stand up well. But that's really ok - it's got a nice compartment for my notebook, a big pocket for holding cables and stuff, a couple of external pockets big enough to hold a phone and an iPod, say, and the interior pocket of the bag, besides the notebook slot, has a big pocket to hold books, magazine, whatever. The strap is comfortable and thick, the bottom has recycled shoe rubber to protect the bag. I got it on sale at EMS last year.
It's something like this one:
http://www.keenfootwear.com/product.aspx?p=597&pc=1665