Before you go off and buy yourself a mobile web site, take a moment to consider why you need to in the first place.
The main reason most people pay for a mobile site is because they need something to quickly and inexpensively pick up all the traffic they are losing from mobile users. Yes, losing.
If someone cannot make heads or tails of your website on their mobile device (because your site is designed for the big screen) they simply leave. They aren't sad. They feel no remorse.
They just know one of your competitors has either got a mobile version of their site or a responsive website that looks good no matter what device they are using to view it.
Local businesses who have spent a lot of money on their website recently, but it wasn't built for all screens, still have sticker shock and usually go for a cheap mobile version of their site. Not a bad idea until you can catch up with the times a bit later when your budget allows.
But if your business is due for a completely updated site (i.e. you had yours done pre-2010) then you don't need to worry about mobile sites at all.
Today's most advanced sites are called responsive because they are built to perform well on any screen. From cell phones to tablets, laptops, and desktops.
Check out this cool tool that will show you what a responsive site is supposed to do on each type of device. (You can even load your site and see how it looks on different screens.)
Here's are some examples of responsive sites. Take a look at them on your phone. You will see that they load quickly and resize themselves in different ways to fit the screen they are being viewed with.
The jury is still out just how and when responsive design is going become the default in web design. Lots of people are still building mobile sites and will for awhile yet. That's because well over 50% of Facebook users are using their phones to interact on Facebook.
Meaning, if you just posted a link to your site on your Facebook business page, over 50% of your "Fans" are going to be clicking the link on their phones. What will they see when they get there? Scary to think about the wasted traffic and business.
If its time for a new design of your local business site, and you want to be as forward compatible as possible while serving every precious visitor with a smooth experience, you should ask about building a responsive site.
For further information on responsive design, check out "4 Points That Make Responsive Design Worthwhile"