I'm not sure if this is the right forum to post this in, but most of the lock threads my searches have turned up have been in the commuting subforum.
OK, so I did some research on locks, and I really wanted a U-Lock for the lightness and security. But then I remembered that at my school, the bike racks are almost all the kind that just has a rail on the ground to secure the front tire to. Since it wouldn't be too hard to remove the front tire and steal the rest of the bike, I've decided to get a single chain lock instead, long enough to loop up through the front wheel and part of the frame. That way it's more secure than a cable lock, more flexible than a U-lock, and doesn't have a weak point like a U-lock/cable lock combo would. I looked around a little and came upon the Kryptonite New York 2010 and the Onguard Beast. They're both long enough, but I looked at them in person and realized how heavy they were. Are there lighter options that are still pretty secure? My campus is low-crime, and most people just use cable locks. I've only seen a few U's and can't recall seeing any chains. Perhaps other bikes would be easier to steal, then? Also, my particular bike is higher-end than most, but there are certainly much more expensive bikes there. It's a newly bought bike, but it's an older version of the model that I got on clearance, so I hope it doesn't attract as much attention. Also, it's a Kona, which is a brand I haven't seen at all on campus. Maybe thieves would go for more popular brands to avoid suspicion when selling the bikes? Finally, it will be locked up during classes in the daytime in fairly high-traffic areas; I plan to keep it in my room during the night. Maybe I can settle for a lighter, lower security chain? Thank you in advance for the replies....

Could you leave the heavy chain locked up to the rack? If you could do that then you could get a u-lock to carry with you when you're not at school.

I use a Kryptonite 1217 because it can go through the frame and both wheels while still having enough slack to attach it to almost anything. The bad is that it weighs 13lbs. I through it in my backpack and forget about it as I know there really is no better security I can get. (except the new york Fahgettaboudit chain). Just my .02 but I love my chain despite the weight and works great.

And just for reference as to its versatility.

On our tandem bike we use a steel woven cable and a very tiny titanium combination lock. Works for us.

For future reference, you may get better/more responses if you used paragraphs. Or at least shorter sentences punctuated by spaces.

You don't have to buy a fancy chain and lock from a bike accessory retailer. I opted for a 4' length of the heaviest galvanized chain at Home Depot. HD and other similar stores also sell excellent locks used by construction contractors. You can be innovative and make your own chain cover. That is, if you feel you need one. I leave mine at work every day. It reserves my spot.

I also have a Ulock and a short cable These always go with me, except on ride rides. I have even put a padlock through the disc rotor on my front wheel at times, just to deter potential thieves .

You don't have to spend a fortune on bicycle security. You do have to spend a little time observing, thinking and shopping.

+1 One of the most important things I ever learned in life is that marketers are the last people you should trust, so much so that my starting point when shopping for something is to only consider things which are not advertised for what I want.

A non-bike specific chain will be better and cheaper.

I bought a 5 foot 1/2" twisted steel cable with nylon shield and eyelets from Lowes for about $7. Used for locking up tools and ladders and such. Found a Masterlock padlock with boron carbide octagonal shackle for about $12. Sure, you could get through the thing eventually with a saw, or you might be able to take a very strong bolt cutter to the shackle, but no lock is unbeatable. Chances are, this $20 solution will be more than enough security for your bike. It's cheaper, and lighter to be aware of your bike's location, and not leave it unattended for very long periods even if it's locked.