Dollar has locations up and down the strip, their website can tell you exactly where.

If you choose not to rent your car from the airport, you will save airport taxes (approx 10%) but you will need to get from the airport to your hotel. I would suggest using Las Vegas Limo, they charge $4.50 per person, and you share a limo (not a crappy van) with up to 5 other people.

If you do choose dollar, use code DESTC - should get you a car for $19.95 a day, and you should be able to drop anywhere. You may have to call their 800 number to get the drop feature noted in your reservation...

Good Luck!