What hydration system should I use for multiple activities? Looking for a hydration pack/system that I can use for cycling, running, snowboarding and (by removing the bladder and putting it into my travel pack) backpacking across Europe.

My requirements are pretty simple:


Small
2L capacity (or around that mark)
Light
Minimal - no extra storage or other bells and whistles are necessary
Reasonably strong/good quality


What do you recommend?

At this stage I'm interested in this bag by Deuter.

I will actually be using it for a lot more snow boarding than anything as it is now winter in Melbourne, so the smaller the better as I want it to go under my jacket (I know this is a QA for bike riders, but just thought it was worth the mention).
If you're looking to go minimal footprint, with no storage, why not go no bag? These definitely have downsides, but they fit under anything, with any type of clothing, or sport.

Camelbak VeloBak Hydration Jersey

or 

Camelbak Racebak Hydration Vest

Downsides include water which must be cooled, or will heat to body temp.

Check out the linked reviews.