I recently got a knife holster from wallmart that workes great.
It Seems to be of decent quality. Much better than the multi tool sheath at wallmart that has been mentiond befor. Though they are from the same manufactuer. the price is under $3.00 They can be found in the camping section over by the little camping trinkets like compases, ponchoes, whistles, ect.
My favorite feature is that there is enough room in the bottom for 2 spare batteries. I do not have a tsp button on mine but I believe that there is enough space at the top that one could fit. If it was tight then you could always leav out one of the batteries and you would be fine.