Ketchup n imli ki chutney. Mix em up. Sounds weird......but oh so good. You get this lovely tangy sauce. I should market it if it hasn't been done already, lol. And to back me up....PSquared has tried it......and agrees that ketchamarind is good.
Yogurt or mint chutney mixed with ketchup is not bad.....to me anyways.
I love condiments......so apart from the above example, here's another strange concoction I make. From a jar of achar....I take a bit of achar masala with mayonnaise. Oh so good.
Apple juice......and 7up or sprite. Pour a little bit of the soda into the apple juice and you get apple soda.