3G access is non-existent and all access is via WiFi either from your accommondation or from many/most cafes. However, the internet is slow (and I mean slow!). Skype is banned from many or most places and speeds are barely sufficient to collect email and/or write a post or two to a blog. Having said all that, all you need is a laptop with a wireless ability (meaning just about everything these days) so you don't need anything special. We always travel with an old 12" mac powerbook as it is small enough to fit in a hotel room safe - old and slow but tough and practical.
Have a safe trip. If you haven't been before, Bali is a wonderful island with lots to explore. almost 10 years ago