I am planning a trip to Las Vegas for a diving show.
I use the website Kayak a lot for planning my air travel. They own a website called Jetsetter which sends emails about nice hotels in nice destinations, and supposedly great deals. I started getting their emails and tried them out, booking a hotel in Vegas through them. I was not impressed with them and cannot recommend them (I do highly recommend booking.com and tripadvisor, both of whom I use regularly to book hotels).
Jetsetter takes your money immediately after you reserve your hotel room -- in full. They not offer any way to cancel your hotel room on their website. You have to send an email or call, which I always find suspicious (it's just too easy for a company that has your money to not return emails or calls). Because they take your money immediately, there's no recourse of filing a credit card dispute if you want your money back. Being forced to call or email to cancel a reservation is 50% of the problem in my book: they only answer phones from 9am-6pm EST. I have also found that the prices on Jetsetter are not great deals -- other booking sites had lower prices.
It's too bad.