Let's see what we've got here:
1. Tuk-tuks! Tuk-tuks are practically the official vehicle of Thailand. (If you haven't seen one, it's basically a motorcycle that has been retrofitted to have a back seat. The driver is in the middle and a covered bench seat straddles the back wheel, and two wheels on either side were added so that it won't fall over, dumping it's cargo into the swarm of traffic in Bangkok.) It's open-air and loud, hence where (I'm assuming) it got its name. They're relatively agile in traffic, which means you can sometimes get places quicker. Not good for long-long distances, unless you've got time to kill. Good for stealing tipsy kisses as you tend to smush into any companion with you in the back. Or, at least, I did ;)
2. Open-backed trucks. This is the preferred method of travel in Chiang Mai. I've seen a few in Bangkok, but they seem to be half of the car fleet in CM. It's a truck with a covered (and occasionally tricked-out!) bed, with benches down the sides, over the wheel wells. Oh, and there isn't a tailgate, so hang on! Ten people can fit in one of these, and the driver can stop to pick up more people at anytime during the route. As with almost all transport in Thailand, negotiate your price before you get on/in. We rode a couple of these up to Wat Doi Suthep. Take one to the zoo, and then there's another line waiting to ferry people up the mountain to the temple. It's an established routine, and we haggled hard on the price but couldn't get them to budge - they got smart and printed signs with pricing for individuals, or if you can get a group of 10 they'll cut you a deal (you can band together with other temple-goers).
3. Moto-taxis. Literally a motorcycle taxi! Negotiate a price and hop on. I've seen girls sitting side-saddle if wearing a skirt, so don't let that stop you! Good for one person. Bad for more than one person. Very fun! (Just don't tell your mother that you don't get a helmet.) (Hi, mom!) (Calm down, it was only four blocks and we only drove on the wrong side of the road twice!) In Bangkok the drivers wear orange vests and hang out at popular street corners. Motorbikes are awesome in the cities because they don't wait I traffic at lights, they weave their way to the front of the line and then take off ten seconds before the light changes. Good if you're in a hurry!
4. Water buses. There are 15+ docks along the river through Bangkok that serve as stops for the public water bus system (I think this might also be called water taxi, but it's much more like a bus). It costs 15 baht, or about 50 cents to go as far as you want. These boats are loooong and hold a lot of people. There are seats and benches, but stand at the railing and you can get a poorman's tour of the sights. I rode this today from Khaosan Road (sp?) down to the main dock without issue, but had to switch to the south route to get to my final destination and that boat was no where to be seen for a good 20 minutes. (I wound up befriending a couple of Australians who were staying at the Chatrium Hotel - close enough to the stop I wanted - which runs a free water shuttle from the Central Pier to the hotel, and hitchhiked with them. So if you're in a pinch, I'd say go for it.)
5. River ferries. Operate in tandem but independently from the water buses. These boats just hop from one bank to the other, back and forth all day long. Sometimes they are at the same piers, but more often than not they're separate. To get to a pier, take the smallest possible alley that will get you from the street to the water. Bonus points if it's somewhere that looks like you shouldn't be there.
6. Regular taxis. Negotiate your price first or insist they run the meter. Cab drivers seem to be really honest, compared to other places we've been. One company's cars are painted pink!
7. The Skytrain. This has an official acronym but I don't know what it is or what it stands for (that's what Britton is for in my life.) It works like mass transit. You pay a rate based on your destination, and I never tried to get off at a different stop, so I can't vouch for sure that you'd be ok, but my thought would be that as long as you exit before your original plan you'd be fine (but maybe not after, as that would potentially cost more). This is also a good way to see the city without paying a fortune since it's above everything.
8. Subway. There is a subway. I didn't use it. Guess I didn't need it?
9. There are regular buses, too, but I don't speak Thai. So I don't know the routes. I'm sorry. :( I'll try to learn Thai next time I come to Thailand. Anthropology-major fail.
I don't have pics of all of those because we used Britton's phone for photos. So here's a too-dark photo of Bangkok's 2013 Car Free day logo!