I supposed it's kinda common for cabbies/taxis to charge more...especially when they noticed that you're no locals. There're so many cabs around Bandung...there's not problem at all getting around there. The only problem is almost all of these cabbies (except Blue Bird) don't use meter...they simply charge you whatever they want. So, a trip that actually cost around Rp20,000 can go up to Rp50,000 or even more.
Fun Alternatives: If you dare enough...take the Angkut that charges less than cabbies but you need to know which Angkut goes where...well, no problem really...just ask around. Another option is to get the number for Blue Bird taxi...or you can just wait for them by the street. Blue Bird cabbies seemed to be more honest n use the meter for cabs fare. Minimum charges for Blue Bird is Rp15,000.
Don't take trishaws unless you really have to. A really short trip I had with my mum cost us Rp50,000 (we can actually have 2 trips on Blue Bird with that). Then, they will sort of purposely take you round n round...finally...they'll charged you with whatever rates they like.
For you who are looking for a street party scene, this may not be a tourist trap. But I am writing this because someone has complained for being trapped here, which makes him really upset.
Here it goes...
Every Saturday night, Bandung youngsters gather on Dago Street (a.k.a. Juanda Street) from the lower Dago in front of Holiday Inn hotel. So if you are going somewhere by car, avoid Dago/Juanda Street (especially Lower Dago)!
Unique Suggestions: If you are in, there is nothing you can do except being patient.
Fun Alternatives: Find an alternative way. Your Bandung city map should be very useful. See my Packing List tip to know which map I recommend.
The trip on it's own right is not a tourist trap, the jungle trek through the hills is very nice. You will need an official guide, there are many at the start point. There will be an entourage of a couple of friendly people who will follow on the journey striking up conversations and offer assistance along the way. When you reach the destination(hot springs) and you sit down to warm your feet after the trek out of all their back packs they will try and sell you jewelry, semi precious stones, post cards etc... and they are very persistent. The prices they sell it for are about 4-5 times the normal price. Be warned.