Wow, I wish I'd seen this thread earlier.
Hoya, go to Myspace and add the Super Insurgent Group of Intemperance Talent to your friends list, and say hello from Jaguar and myself. Indonesia has a tiny but lively indie rock scene and if you're lucky you might be able to catch a great show and meet some really nice people.
In Java, be sure to visit Yogyakarta a cool city where multiple universities give it a college town vibe, Indonesian style. Mt. Merapi, an occasionally-active volcano, is just an hours drive away and worth the trip.
Bali is beautiful, but get away from the tourist traps full of drunken and annoying Aussies to the smaller towns. Also avoid big resorts. Ubud, inland, is a spiritual magical place and well worth a visit.
Jakarta's probably worth no more than a day or two (I lived there seven months), if you'll be spending any time there I can give you a few pub and restaurant tips.
If I could go back I'd spend more time exploring Java, and visit the area around Anak Krakatau, where Krakatoa blew up and a new volcano is being formed.
For the 30-hour plane ride to Indonesia I recommend the book "Krakatoa," a great read which will give you a flavor for the history and culture of the country.
Finally if you need any more specific tips feel free to message me... and you may get some ideas from my photostream of Indonesia pics:
http://www.flickr.com/search/?q=indonesia&w=77926160%40N00 Oh yes, travelers checks -- I have traveled all over the world and never needed them. I don't quite understand the concept. Seems kinda anachronistic, like the old notion that paper airline tickets were the equivalent of cash.