like your hot drink, you can use it as a rich veggie stock, too. makes an amazing lentil and tomato soup, and is excellent with a splodge of ketchup and some herbs for a flavour base in shepherdless pie, and in things like cornish pasties- cos its so deep, rich and earthy.
its good on sandwiches.... marmite and salad, marmite and grated carrot (and hummus, even?!) marmite, tofu and cucumber, marmite, roasted red pepper, mushroom, tomato and onion, marmite and faux meat, etc. toasted sandwiches are good too- grilled 'cheese' and marmite (like a cheats welsh rarebit), marmite on toast with baked beans piled on the top, etc.
when i was younger we used to spread it onto rolled out puff pastry, cut it into strips, and then roll them up into spirals, or twist and plait them, then bake, for savoury cheesestick type things. those were very good. probably not amazingly healthy with the amount of pastry we got through, but decidedly tasty.