Even setting aside the Jamis discount, the OP stated he is new to cycling, and I would never recommend a single-speed bike to someone who is not seriously skilled and very strong.

*scratches head*

Um, that's not a SS that was linked to- it's an 8spd IGH.

Lieren, here's a little info about what an IGH is:

http://en.wikipedia.org/wiki/Hub_gear

Not really enough information to tell you anything useful.

- How far do you ride? The Commuter line is great for short commutes, but isn't terribly efficient and could leave you quite tired after a long one.

- What kind of hills are you looking at? The IGH is enough for most situations, but doesn't give you the same range as modern derailleur systems. If you've got constant ups and downs of widely differing grades, it may be less than ideal.

- When you say "exercise," what do you have in mind? From the shortlisted styles, I'm guessing you're not planning on off-road mountain biking, but if you are, then obviously there's some equipment demands to that. If you have visions of yourself racing bikes, then that also will be a driving factor in your decision, though racing bikes are a very poor choice for commuting (handle loads poorly, high value target for thieves). If your vision of exercise is to go for a long ride on paved roads and well maintained trails, with no view to speed, then the touring line is more up your alley.

Four years on, I still love my Aurora, and I'd buy it again. The change to bar-end shifters, though, is not my thing, so I'd probably be looking for other models of similar design.

My commute to class would be a mile to a mile and a half at most. The area is pretty "hilly" so there's a decent amount of uphill and downhill. In terms of exercise, I'd probably only be doing a couple miles at a time, at most 30 min.

IMO, as someone who's in a vaguely similar position (grad student), the best thing you can do is to find a nice, solid old bike and bring it to a local shop to replace and tune all the necessary bits. You can usually find an old frame for cheap, and basic part restoration is also pretty good.

Also, a lot of colleges will have a bike co-op, which is usually a great place to find refurbished bikes. http://www.quadbikes.org/ is where I go, for example.

I say all this because anything that looks new on a college campus is going to be a target for theft, and few colleges provide indoor bike storage.

Good luck!

I'm surprised no one has mentioned the Bosanova. I like the Auroras, but an agile and shorter mountain bike often works better around town. That's what the Bosanova was built for. Short, agile road bike that you can equip with fenders and rack. Steel frame for comfort and durability.

I'm surprised this didn't come up sooner. I do live in a big city with lots of colleges/universities and I can't even imagine parking a nice new bike like a jamis near a campus, every day, for the same amount of time. Might as well put a giant sign on it that says "Please steal this bike or bike parts between the hours of 9am to 5:30pm".

Get a beater, get something that won't break your heart when it gets stolen.

I have been riding an Allegro 1 for over 4 years now. I upgraded from my beater bike because it just kept having too many mechanicals. I road the bike for about a month and broke a spoke. Bummer! fixed it and promptly broke another. This time the shop saw that the rear wheel was slightly warped. No problem, since it was still under warranty. They agreed to upgrade the wheels to some nicer ones. About a year later there were about 7 linear cracks on the replacement wheel. Got another new wheel out of the deal. While I was there a guy came in who is a student at a local college with a Jamis Coda with both wheels so warped that you could see it at a glance. The Aurora looks like it has better components overall. Go for better quality wheels!!!

Is it possible that newer models might be better?

The Coda has double wall rims, 14g stainless steel spokes and (IIRC) brass nipples. They shouldn't fail or warp unless they were improperly trued/built or they've been subjected to excessive loads. I've run lesser wheels for years without any issues whatsoever.

This. You don't want anything that looks very nice on the bike... those are the first to go. This includes accessories... if you have a frame-mounted pump, lights, whatever, take them with you. I was lazy and left some dollar-store bungee cords I use to strap down my bag with, and even those got snatched. You might also keep an eye out for bike "kitchens". Similar to co-ops, but usually more like just a shared shop space. Usually you pay a nominal fee and can use their tools. Great way to learn how to maintain the bike for cheap until you can get your own tools (if you so choose).

Only other suggestion I'd have is to go the folding route. Citizen Bike has some cheap ones, but I've heard mixed reviews. Bromptons are really popular with small folded size, but pricey. Then again, theft is less of an issue. Lots in-between those two price points... might stop by the folding sub-forum to get some ideas. I think for mild to moderate commuting the Citizen Bikes are probably OK. I may be picking one up in a few months, so I guess we'll see. I have some night classes that have me getting out at about 9:30pm, and I'm a little concerned about my Novara Randonee getting stolen at some point. I'd be more comfortable if I can just fold it up, throw it in a bag and take it with me.

My local bike store said they were out of the Codas... what would the main difference be between a Coda and Allegro?

There are small differences in the geometry but not to any great degree. Really the biggest difference is in frame material, chromoly vs 6061 alu.

Ok thanks.