In the past 3 months I've cut my "monthly's" in half by:
- Paying off and closing old unused accounts.  I know it's not ideal for credit, but the temptation of spending followed by paying interest on already high prices is easier if it's not there.
- Reducing my utility bill... in the coldest month of the winter my bill for a 1BR apt with poor insulation was about $215, this past month it was $67 and should be below $50 this month.  I turned the thermostat off for the past few months and I haven't been uncomfortable, I turned my water heater down and now my gas usage should be much, much lower.
- I called my insurance agent and renegotiated my rates... cut that in half and since I had already paid for the current time at the rate that was twice as much, I won't owe again until next year.
- Removed a bunch of crap from my car to raise my MPG just a slight bit more... I'm going to give the bus a whirl starting June 1.
- Stopped going out to eat for lunches... I was going out everyday... cut that to just Fridays... then I cut Fridays out because the people I went with always wanted to go to places where it costs at least $10 for a meal (Plus tip.) and they always wasted an extra half hour there... which was a half hour I wasn't getting paid for.  I also only take half-hour lunches now so I can leave a half hour early and not have to waste gas in traffic. 
- Stopped going to bars... pretty much stopped buying beer unless I'm going to a party.  I don't miss it.
- I don't have cable (only cable internet).  I had a "first 6 months" price of 29.95, and after that I simply called and asked if I could still have it for $29.95 and said I was going to cancel if it went up to $44.95.  $1/day for internet is acceptable... if it went up I could deal with DSL at $25/mo instead.  
- Drink water.  No bottled drinks... maybe a soda or something as a treat from time to time, but no more "a 2-Liter every couple of days".  
- I had a friend who moved away to be with his family in September, and just decided to move back.  I'm renting out my living room to him for half of my rent.  My apartment is set up in a way where he could find a door on craigslist and it would be just like a second bedroom.  The door to the outside is in a hallway and the framing to the living room has a door frame (just no door.), so adding one wouldn't destroy anything.
- Buy store brand products, avoid "ready made" products like Chef Boyardee, frozen microwave meals... also just eating a proper portion and having enough to take to work for lunch saves a ton and is doing my gut some favors.
- Walk when possible.  I live within walking distance of the grocery store, if I go once a week on foot I'll save money by not driving there... but also I don't buy crap I don't need because then I have to carry it back, too.  The only downfall is that my bread usually gets squished. 

- Shop at dollar stores for detergent a paper goods.  Same brands, much lower prices.  Might make you feel a little trashy, but it's worth it.
I'm throwing every spare penny I can into savings and hope to be buying a house late this year or early to mid next year as the housing prices are supposed to near their "valley" at that time in my area.
Great read for a 20-something that just doesn't quite understand finances.