What are you doing in Las Vegas and how long are you going for? Lots has been written about it so you’ll need very well written, interesting content to stand out.
Think about who you are writing for. I write mine aimed at friends (though really, I write it because I enjoy it), the odd stranger finds it interesting too.
What’s the theme? What will make it stand out? How often will you update it? What will keep people coming back?
EDIT – Just had a look. Are you just going there for a short holiday? Will the blog be dead after the holiday? And why bother with an advert box?