Is there a website that has cool ones for sale? Maybe some metal related band ones?
It's really quick to just slap on a bandanna and go about the day.
Join a gang =)
whatever you do, don't wear RED or BLUE,
as those are gang-related colors, and you may get
stopped by the cops, or worse, get killed by
someone wearing a rival color....
You don't say... So THAT's the cause of the discriminating stares I've been receiving from figures of authority whenever I go out wearing blue atop my head...
We have a big problem with that over here in Detroit. The blue color belongs to the gang the "crytps" and the red one belongs to the "bloods". They spray paint there names all over and if one gang spray paints over the other gangs writing, they go crazy and shoot the other gang.
I've been wearing a blue one a lot lately.
Good thing I live in the midwest. :)

Probably depends on what you wear WITH the bandanna and how old you are. I wear them all the time, including red and blue ones, and I live in a city with gangs. I am 56 years old, though, and also, gang members don't dress like hippies. I couldn't look like a gang member if I wanted to. I'd wear the bandanna wrong, I'd wear the wrong clothes, or I'd have my hair the wrong length. They'd just laugh at me if I tried. What they see, though, without my even trying, is that I am genuinely something else.
If you are a teen, wear saggy clothes, and have the right hair style, I can see, though, how getting confused with a gang member might be a problem.
You might be able to buy some at markets; that's how I got my first pair about a year ago. Ever since Eminem wore one in public, bandanas became something of a hot commodity (again), so my guess is that you may be able to pick some up at trendy stores at typical malls.
Also, with Hulk Hogan's career resurgance, you might be able to find Hulkamania-based durags in typical clothing outlets as well.
As for metal bandanas, I guess your best bet is to try the official website of whatever band you're into. You might be able to find them on Ebay as well. Some bands sell such merchandise when they go on tour, but it's usually pretty expensive: Aerosmith was charging $10 for a bandana with their band's logo on it, but I'd rather support artists by purchasing their merchandise at shows than by buying their CDs in record stores (Atleast in the former situation, the band makes some profit, whereas in the later, the artists make next to nothing while the record companies reaps the lion's share of income from CD sales).
I live in NY, can't really wear banadanas. Every gang has their own color, even pink is taken.