Freedict
Freedict English-Indonesian dictionary provides instant translation of English words and phrases up to 49 characters long. It includes links to other sites of interest about Indonesia, as well as freedict.com online translators for other languages.
http://www.freedict.com/onldict/ind.html

Logos
Logos bills itself as the largest freely accessible multilingual dictionary on the web, with dictionaries in 232 languages. English words and phrases can be translated into Indonesian at the touch of a button. Logos also features a universal conjugator, children’s dictionary, and more than 43,000 online books in over 100 languages, including 44 in Indonesian.
http://www.logos.it/

Dicts
This English-Indonesian dictionary translates words from both languages instantly, and allows the user to type in just part of a word to find all possible matches. The site also features a picture dictionary.
http://dicts.info/ud.php?l1=Indonesian&l2=

Ectaco
This site offers instant translations of English and Indonesian words. This free English-Indonesian dictionary contains 400,000 words.
http://www.ectaco.co.uk/English-Indonesian-Dictionary/