Topic title kind of says it all. I got a $35 reversible go board (13x13 and 9x9) with some melamine stones and plastic bowls. To my surprise, the lids don't stay on any better than with any other bowl. Anyone know a source for ones with firmly attached lids? I'd appreciate detail; rather than saying "use Tupperware," at least a picture would be nice. Thanks!

I have used disposable ziploc containers with screw on tops:

http://www.walmart.com/ip/Ziploc-Twist-N-Loc-S-Round-Containers-Lids-3ct/14862647

They should be fine for stones that aren't too big.

Thanks skydyr! I also found this from Senseis, for the convenience of future searchers:

TBH, I thought the lids were 'supposed' to be loose ?

I need some sort of straps for when I carry my bowls to the cafe though.

That's what I thought so too.

One of my sets, purchased from Yellow Mountain Imports, came with a pair of very convenient velcro straps. Perhaps they sell them as a separate item? It also came with a special carrying bag (but I am not satisfied with that item; handle broke).

Most of us struggle with this sooner or later and/or perhaps make people even refrain from taking a set with them. AFAIK there is no practical, cheap solution readily available on the market (except perhaps YMI), so I think many came up with there own personal solution, tying something together?
Else, you may be interested in a 'paulownia' case, often used in Japan, perfect for both storage and transportation. More expensive, but recommendable.