Entering races for 13 years I've now got a houseful of mementoes. Hard to get away from the fact that' there's a runner in the house.
Best mementoes: engraved tumblers/whisky glasses, slate coasters, a toilet bag, technical Ts especially Montane ones, cotton Ts, Christmas puddings
I have about four drawers of cotton T's. The ill-fitting ones or ones with pompous messages on get used straightaway for decorating/dirty jobs and get thrown out. Most of the rest I enjoy wearing - I've never had to buy a T for 13 years - and once faded they join the pile of ones to be used for dirty jobs or as rags.
Middling mementoes: mugs, medals (remember not to put the medal round your neck after finishing - they will get salt on them and quickly rust), tea towels, paperweights, sponsor's food samples, shoe bags
Worst mementoes; nasty plastic drink bottles, nylon bum bags, certificates where you have to fill in your race details yourself, long-sleeved cotton Ts (which I don't wear)
I have bought a few race photos. They have to be good and include the date and finish time.
There's probably other stuff, but I can't think of any more at the moment.