Originally Posted by
tsastor
Elsewhere in Europe, tipping is not very common but
if I don't know the customs, I always try to remember to find out. After that, the same applies for me in Europe as in the U.S., i.e. tip when it is required but avoid those places when you can.

Therein lies the most important point. In the United States, it is
local custom to tip. Europeans often seem so keen on foreign travelers respecting THEIR customs, but completely neglect cultural sensitivity while visiting the US.
Now, if you're just endeavoring to only participate in activities which won't require a tip, then that's fine and I commend you for your budget approach to travel. However, don't "not tip" just because you don't think you should have to "because we don't tip in Europe."