You might need to open up the port the site is running on. Go to Control Panel -> Windows Firewall -> Advanced Settings. Click on Inbound Rules and Add a New Rule, select Port and run through the wizard, using the port number the site is assigned in IIS.
More details here: http://windows.microsoft.com/en-us/windows/open-port-windows-firewall#1TC=windows-7
You should be able to view it on your phone now by using your ip and port.
To run your site off IIS:
You'll need to first enabled IIS in Windows, you can use the link Humpy posted in his response.
Then once its enabled, open it up and expand the Sites folder, and then right click and Add a new site. Give it a name, point it to the directory your site is running off and assign it a port. Test it by going to locahost:{yourport}. You might have to set permissions by selecting your site, and then hitting the Edit Permissions link in IIS, select the security tab, hit Edit, then Add and use the application pool the site is running off, so IIS AppPool\{yoursite name}. Give it full permissions since its running locally and then hit the site again in the browser.