Panniers vs. Backpack for commute

[KnottedYet]

Consider Wald folding pannier baskets. They are pretty inexpensive (about $35-40 for a pair at the LBS), no-one wants to steal them, they are firmly attached, they hold a ton, they are always on your bike so you are always ready to carry stuff.

And made in the USA.

Trek420 does her SF commuting and shopping using Wald baskets.

You can throw your beloved backpack into one of the baskets (left side, to make you wider to cars) on a light day, toss books into a shopping bag and into the other basket on a heavy day. And yes, there is no problem at all using only one basket on one side, you will not be off balance. There are bungee nets (about $6) to hold awkward loads in the baskets.

http://waldsports.com/index.cfm/wald...ingbasket.html

You can hang lights and reflectors off the wire mesh. They are unobtrusive when folded flat. They don't rattle (and if you find a rattle, fix it with a layer of electrical tape).

If it rains you put your stuff in a plastic bag before loading it into the basket, or if you want to be extra guaranteed dry, use a rafter's dry-bag. A dry-bag is much cheaper than something like an Ortleib waterproof pannier.