Swag, tchotchkes, gewgaws, knickknacks, baubles, lagniappes, trinkets, kitsch, promos, brand wear, branded items, ad specialities, logoed stuff, crap, perk, giveaway, gift, imprintable, present, throw-in, tradeshow toy, or promotional product.
Lots of different names for an item you put your logo on to make an impression and build your brand. An effective marketing tool. A promotional powerhouse that can deliver more bang for your buck than any other promotional medium.
So, what do you call them?