I just say wear the tanktop and not care if anyone sees your bra straps! Or get the clear ones... thats what I do
If guys can walk around with their boxers hanging out and some girls walk around with their thongs (ew ew ew) hanging out... wear your bra with a tanktop!
and for tube tops and (in my opinion) those ugly one shouldered numbers (UGH UGH hate them as much as capri pants!) you dont need them anyway!

(again thats my opnion, I dont care for them!

)
If you do, then the clear straps could work...
luvnstuff
alison