Airfare Tips?

So I spent the better part of my day hunting around online for a deal on airline tickets to Los Angeles in October. I will be flying from Madison, Wisconsin out to California to visit my brother, who moved there at the beginning of this year. I ended up getting what I consider to be a pretty darn good deal to fly roundtrip out there, $240. I thought that I would compile a list of the few things I've learned about purchasing airfare, little tips and such, and invite people to add to it. Please leave a comment if you've got some great insider info, or a good story, or whatever.

What (little) I know:

* It seems that all of the travel websites (Expedia, Travelocity, Orbitz, etc.) are usually around the same price. Most of the time its only the difference of a dollar or so.

* The worst days to fly are on a Friday or Sunday when everyone else wants to fly out so as maximize weekends.

* The best days to fly are on early weekdays or on Saturdays. Most people don't want to waste the middle of their weekend flying, so if you are willing to do so (as I was in this case), its usually a better deal.

* This one is only useful for Wisconsin locals, but if you live in the southern part of the state as I do, Madison is generally more expensive to fly out of than Milwaukee, Rockford, or Chicago. HOWEVER, it seems that Madison has some good deals lately, as that is where I am flying out of to go to California, and when compared to Milwaukee there was only a $10-15 difference. If you are flying out of the country, you might as well just go to O'Hare in Chicago. The bus ride from Madison is $25 and takes you right to the airport, hassle free, and its usually still cheaper than the Madison airport.

* These days, try not to check any luggage if you can since you have to pay for it. On my recent flights both to Europe and Alaska I was able to carry on a guitar AND a backpack (I'm talking a mid-sized backpacking pack with an internal frame).

* I think that there are some companies, such as Southwest Airlines, that do not book through sites like Expedia, and do provide good deals on their own. I briefly searched earlier today for a list of airlines that don't use travel websites to sell tickets, and could not find one, but that would be extremely useful.

I think thats all I can think of for now, but please feel free to make your own suggestions and correct me or provide your own tips!