Having Internet access during traveling is almost mandatory for me as I have to regularly check business emails as well as responding to customers inquiries. Many hotels offers free wifi or Internet connection during your stay. We can find free hotspot in restaurant and cafe as well.
But for those who wants to get connected all the time, whether using Blackberry, iPhone, or other mobile devices, finding free hotspot means you can't be mobile as you have to sit on free hotspot location to get connected. The solution is clear, you have to pay for data plan. This will also eliminate your necessity to choose lousy hotel because they offer free Internet service.
First option is you have to buy local GSM SIM card, but you will loose ability to be contacted with your Indonesian number. This may also more expensive for Internet usage only, but for cheap local calls you must choose this option.
The other option is to bring your own Indonesian number and activate
roaming service. You can be reached using your own number, but beware of
expensive roaming rate. Apparently there is another plus point of
bringing your own country GSM: Unlimited Internet with flat rate.