I want to start commuting by bike, but I am unsure how to go about selecting which bike to buy. Of all threads I've read, the type of bike would "depend on [my] needs." I am not too intense of a biker and am just looking to get from point A to point B, which is usually around 3-5 miles on bike paths and lanes. I would definitely prefer something lightweight that is easy to carry up-and-down stairs.
I'm a college student, so I don't have that big of a budget either. I looked at the Commuter Bicycle Pics thread and a lot of the bikes I saw were around $1,000. Can anyone recommend a good bike that is under $500?
There are a few that I have found (below) but, without being able to look at it in person, it's hard to tell whether they would be good for me. So, I'd love to hear any thoughts or opinions.