Most visitors opt to travel by taxi, which is cheap and occasionally even fast. There are a multitude of taxi companies of varying degrees of dependability, but Blue Bird group (tel. +62-21-7981001, 24 hours) is known for their reliability, has an efficient telephone order service and will among other things actually use the meter. The Blue Bird group also runs Silver Bird, Morante, Cendrawasih and Pusaka Nuri taxis; the Silver Birds "executive taxi" charges a premium.
A cheaper option is to take a TARIF BAWAH (low tariff) taxi - Putra (dark blue) is regarded as good safe TARIF BAWAH taxis, though not of quite the same standard as Blue Bird. These can work out about half the cost of taxis such as Blue Bird, which can be significant if you take a lot of taxis in Jakarta traffic.
Some other large, generally reliable companies include Taxiku, Express , Dian Taksi, and newly established Taxicab. You can generally determine a good cabbie by asking "argo?" ("meter?") - if they say no or "tidak", get another taxi.
The standard taxi rate (effective February 2009) is Rp 6000 flagfall, and Rp 3000/km after the first 2 km. Some taxis (marked TARIF BAWAH) use the older, cheaper rate, while Silver Bird is more expensive. Tipping is not necessary but rounding the meter up to the nearest Rp 1000 is expected, so prepare for small changes, or else you will be rounded up to the nearest Rp 5000.
Keep the doors locked and the windows closed when traveling in a Jakartan taxi, as your bag and watch make attractive targets when stuck in a traffic jam or traffic light. Criminal groups in Jakarta often attack passengers who use their cellular phone during traffic jam or near traffic light.
If you always kept a notebook with you, please DO write the taxi number and name, with the driver's name and ID number, so in case you left something in the taxi you can claim it to the taxi company.
Think twice about using the smaller taxi companies if you are alone, and try to know the vague route - the driver might well take you a roundabout route to avoid traffic, but you will know the general direction. Stating your direction clearly and confidently will usually pre-empt any temptation to take you on the long route.
It is also not uncommon for taxi drivers to be recent arrivals in Jakarta - they often don't know their way around and may be relying on you to direct them - establish that they know the way before you get in! Make sure they don't take you the wrong way around the Toll!