We are lucky that our situation allows us to be a one car family. My husband rides his bicycle / public transit to work daily, and after we walk the "big sister" to school, I try to use my bike, with the "little sister". She is growing though - and the trailer seems a bit too small these days.
So looking into a "longbike: for carrying the kids - and cargo.
These bicycles are becoming increasingly popular - and in turn more choices are becoming availalbe. Yesterday's Los Angeles Times weighed out some pros and cons. (You can find the article here.)
What I am looking at:

$1199 Xtracycle Radish
![kona_UTE[1]](http://farm4.static.flickr.com/3186/2922884642_2a595fdf67_m.jpg)
$895 KONA Ute longtail
![transport-bicycle[1]](http://farm4.static.flickr.com/3285/2922033497_9fa2e4809a_m.jpg)
$900 Yuba Mundo Cargo bicycle
Commuting by bicycle? Lots of info at 1 World 2 Wheels.