If yo have a bathroom nearby, you can chill in the tub.
I've also done something similar to billf, where I froze some preboiled water in tupperware containers to make a couple big ice cubes. I did this along with a water bath in the sink to cool the wort quicker on partial boils. Some folks have used storebought ice or ice from a freezer's ice maker, but I wouldn't trust them.
Another thing I do for my partial boils is to put the top up water in the fridge. I buy gallon jugs of drinking water for my brew water, so I put a few in the fridge the night before. Then, I only have to cool my wort down to 90F or so and the top up water takes it the rest of the way down. I keep a couple jugs out at room temp just in case because sometimes I've hit 60F and still have a gallon to go to hit 5 gallons.