Sample Download : http://code.msdn.microsoft.com/CSSharepointGetListIDFromLi-354a5a6f
The sample will show you how to get the list ID, name from the list url by using web service. In this sample, we use Lists.GetListCollection Method of list web Services. It will return a System.Xml.XmlNode object. You can get the value of the attribute "DefaultViewUrl" and append it to site url. After that, you should compare the url with your list url, and then find the list ID value.
You can find more code samples that demonstrate the most typical programming scenarios by using Microsoft All-In-One Code Framework Sample Browser or Sample Browser Visual Studio extension. They give you the flexibility to search samples, download samples on demand, manage the downloaded samples in a centralized place, and automatically be notified about sample updates. If it is the first time that you hear about Microsoft All-In-One Code Framework, please watch the introduction video on Microsoft Showcase, or read the introduction on our homepage http://1code.codeplex.com/.