I have been playing with Microsoft AdCenter API today. The samples do not exactly build in Visual Studio 2008 SP1 without any changes to them. At least for me. After I added "Service Reference" to https://sandboxapi.adcenter.microsoft.com/Api/Advertiser/V5.1/CampaignManagement/CampaignManagementService.svc and integrated code from "How to Check the Status of an Ad Group in C# (V5.1)", I have seen several compile errors. The first one was:

C:\Users\nikolad\Documents\Work\PDC2008\demo\csharp_example\Program.cs(70,21): error CS1501: No overload for method 'GetKeywordAdAssociationsByAdIds' takes '1' arguments

which just opens "pandora box" of errors to follow. Long story short, all of errors can be quickly fixed. Attaching to this thread a source that worked for me. Note: project name was csharp_example, not adCenter as in the original example.