More and more hotels are putting hold amounts on your credit/card for stuff you may charge to your room and at some properties its not an option its required. This hold amount can be released as soon as you check out or take up to two weeks to clear which is annoying to say the least. These hold amounts arn't always disclosed on companies web sites or if are its in tiny print and the desk clerk doesn't always tell you before they run the amount on your card. One interesting point is the amounts and rules can differ from property within the same chain; One such difference is i have not been charged at the "Fremont" downtown but am charged $100 at "The Orleans" both owned by Boyd's. I have my own internet and can watch movies on my laptop and don't use room service unless i have a comp credit so mostly don't want to charge stuff to my room. Here are some recent experiances at some properties.
El Cortez: $50 charged to my account that took two weeks to be credited back
Rio & Flamingo: They run your card but dont charge deposit if you don't want
Fremont: No charge
Orleans: $100 charged to my account released moment you check out
Las Vegas Club: No charge
Golden Nugget: No charge
Rules at different properties change all the time check with your hotel if its an issue for you.