This may be long and wandering, but it's my simplified experience living completely car-free so far, and leading up to what I'm trying to do now about the carless thing. If it doesn't really suit the thread, let me know where to move it to.
I've never driven a car (officially ), in all my 39 years. So far I've been able to get around with just public transit (and sometimes friends when it was simply impossible to do something that way, like moving furniture, etc). I'd ridden a bike (of unknown make) thru gradeschool in rural Texas, and for a while in highschool here in Phoenix, AZ. But the bike got totalled (I just got scrapes) by an idiot driver that pulled out without warning from a hidden driveway across traffic when I was right at the end of the driveway, with no chance at all of stopping. So I went by bus and walking just about everywhere after that, until about 11 years ago, when a coworker gave me her old Murray Biotech bike in trade for one of my music cd's.
That made me never want to use the buses again; having that bike--I'd forgotten the freedom it gives! I did a few add-ons, like a front wire cargo rack on the handle bars, made from an old dot-matrix printer's collection tray, and a regular bike basket set on the back, and some safety lights powered by a bottle generator made of an old toy motor. But eventually, it broke down so often I didn't use it as much, and started having to use more buses and such, because I didn't have enough money to fix it properly, so I just started saving up to replace it instead.
Then, at my 10-year anniversary of employment with CompUSA, I was given a catalog to choose a spiffy gift from, and whaddya know--there's a bike in there. It's probably not a great bike, but it's better than any other I ever had. Columbia 2005 women's 26" comfort bike. They had both men and women's versions, but sometimes I get hurt (traffic is not fun here, and people are mean), so I can't always swing my legs up over the top bar on a men's bike. So I picked women's. I moved the cargo basket over to the new bike, and that let me do my shopping easily again. So much easier than the bus, though it is difficult sometimes finding a safe place to lock it up--many places around here have no bike racks, and sometimes only light posts in the parking lot to lock up to. Some will not allow you to lock up a bike on a signpost, or things like that. I later added a smaller rear basket set to the *front* wheel, so I can carry more in less trips.
I would use just carry bags, but there's a lot of places now that won't let you take a bag in with you, because of shoplifting. So I have to use something people won't steal off the bike, like they do with bags often enough. Thus, the baskets. I gotta put the wire covers with locks on them, though--keep putting that off.
I've discovered after a couple of years though, that I am getting older. Especially after working 11 miles from home, and biking as frequently as possible. So I need a way to go places that doesn't *entirely* depend on my muscle power to get there, leaving me exhausted by the time I arrive. I won't get a car, and there's not much other option besides the bus. Bike-on-bus doesn't work for me, because with the 4 baskets, it wont' fit on the racks with other bikes securely enough for the drivers to be happy.
So I've started working on the electric-assist problem, and have decided that in my typical packrat fashion, I will use only recycled parts in this wherever possible. I started a blog about it to both keep track of what I'm doing, and to attract comments from those with any experience in inventing their own conversions, etc. It's at http://opporknockitytunes.blogspot.com/ for anyone curious or wanting to help.
I've got some prototype ideas going, and currently using a salvaged car power window motor to run some tests. I figure if I'm going to go carless, why not do it with pieces *from* cars that aren't on the road anymore? I've also got another Murray from a friend, and though it's seen better days, it'll be the prototype test vehicle, before I mess up my actual ride.
But if this works out, it will help a lot in getting around town even farther than I could go by pedal power alone. This way, I can pedal when it's not a dangerous strain on me (like when it's 112F and I have to be out in the middle of the day, pedalling against the wind, or sometimes worse, *with* the wind at the same speed I'm going, so I'm basically in dead, hot air!), and when conditions would keep me from arriving in a useful state (or at all), run the motor to help me along. It's only an assist, so it's not intended to move me without me also pedalling, but it will definitely be better than not having it at all.
Once it's all figured out, hopefully some others can adapt what I find out to help *them* deal with being carless. Kind of an "open source electric-assisted bike project".