Getting around Jakarta is a problem. The city layout is chaotic and totally bewildering, traffic is indisputably the worst in South-East Asia with horrendous traffic jams slowing the city to a crawl during rush hour, and the current railway system is inadequate to say the least. The construction of a monorail system, started in 2004, soon ground to a halt over political infighting and the main glimmer of hope is the gradually expanding busway system.
If you're poking around narrow back streets, or just in such a hurry that you're willing to lose a limb to get there, then Jakarta's motorcycle taxis (ojek) might be the ticket for you. Jakarta's ojek services consist of guys with bikes lounging around street corners, who usually shuttle short distances down alleys and roads but will also do longer trips for a price. Agree on the fare before you set off.