Bank.
Seriously, you cant get anything really useful for 6 grand these days. Junk mostly. Yes, you could outfit a nice home theater with that money, but really thats just a waste. If 6 grand is so much to you, then you dont need to be throwing it away on crap.
Put it away. Supposedly because many stocks are low right now, this is a good time to invest. When things turn around you will have massive gains. Bank 3 grand, and invest 3 grand. And know you could practice a little discipline when you had a windfall, instead of going nuts like a child with a c-note in a candy store.