Usability 
Vegas Mobile Concierge is one of few mobile web booking sites I've seen that's actually easy to use. It's main function is finding and booking Las Vegas shows, something it does very well. You pick a show and are presented with the available times and prices, which include all taxes and fees so there are no surprises. Once you choose the number and type of tickets you want you are prompted to use a click to call link to complete the reservation with your credit card details.
Some day all phones will have a mobile wallet to make on device purchasing truly painless. But until then an old fashion voice call is far, far easier than using a web form in any phone browser to complete the tedious business of entering all the details that a credit card purchase requires. While the mobile versions of services like PayPal and Google Checkout are also fairly easy to use, relatively few Vegas visitors are likely to have an account on one of these services and have gone to the trouble of enabling mobile access. Just about everyone who can afford a Las Vegas show has a credit card.
I was rather impressed with the quality of the Vegas Mobile site's mobile web implementation. I don't know who did it but they do clearly understand the both the opportunities and the limits of mobile web services.
The site uses browser detection and adaptation to customize the site to make the most of each mobile browser's capabilities. iPhones, Opera Mini, S60 Webkit. Android phones and most other devices with full-web browsers get a rich presentation with tabs and iPhone style 3D fade section headers (top image). Openwave, Motorola and Nokia S40 "Services" browsers (bottom image) get a simplified design that manages to maintain most of the look and feel of the rich mobile version. There's even a wml variant for old WAP1 phones
I did find a few things that could have been done better. Some of the shows featured on the front page turn out to be sold out when you try to book them. If there are no tickets available why even list these shows? The browser adaptation, while good, is not perfect. The site triggers an Openwave 7 browser bug that makes most of the text an unreadable beige on a beige background. And the wml version has markup errors that will probably prevent it from working on most wml-only phones. In reality both wml-only phones and ones with Openwave 7 are relatively uncommon. Most mobile users will find the Mobile Concierge a very useful way to book the famous live shows when they visit Vegas.
Mobile Concierge is a service of Vegas.com, which is owned by publisher of the Las Vegas Sun daily newspaper and is the biggest booking agency and tour operator in the self-styled "Entertainment Capitol of the World".