Sales
N.B Try not to over-estimate demand... you don't want to find yourself in a situation where your members are having to buy (for example) the candy themselves or give it to people who come into their room just to get rid of it! Planning is important on all funraising events, these have worked great for GLO's and some people have less success with them 
Another idea is to maybe solicit help from those in the community. One of the things we're doing this semester is selling ice cream tickets. For $5 they get a gigantic slice of ice cream pie (it's really good!), and $3.25 of that goes to us. I know companies like the Cookie Corner and Mrs. Fields do similar things with bags of cookies.
Another thing we've done in the past is buy candy and goodies wholesale, put an assortment of them together in a giant bag and sell them for $5. Selling them during exam times is a good idea! Very profitable too.
It is kinda of selling, but we do final grams at the end of every semester. we send out letters to parents (we get them from the registrar). We charge something like $20 a piece. they have food, toys and some stress thingy. our cost is like $4. we make like $1200 a semester. We deliver them by hand. Just make sure you get addresses and phone numbers from parents. we use excel to keep them straight. parents can write their own message. frosh parents love it. they are so worried about their kids. We have a small college (1100) and it is residential. so that helps but you could maybe do it somewhere smaller.
Crafts
Handmaking candles and selling them - for example - for £5.00 and the cheapest one £2.00. The group raised £250.00 in two weeks doing something that was fun for them.
Others
Calling Cards. A fundraiser from an organisation called National Collegiate. They market calling cards to sell on campus, for Greeks and others.
http://www.nccallingcards.com/
T-Shirt sales. Contrary to some experiences, this fundraiser CAN be very effective. But you need to be careful your university's Greek community is large enough to carry it. Otherwise you will be left with a lot of hard to sell shirts! In other words on larger group campuses e.g. during Greek Week if you can ensure beforehand there will be interest then it can be hugely effective and highly lucrative. Obviously you can sell to people other than Greeks too! The website for the company which does this is
http://customink.com/cink/r.jsp?S=BLP. For questions you can email
lilacgirl77@collegeclub.com . For larger quantities, she can even get you a discount on the Customink quoted prices!