In this post Jonathan van de Veen looks into analyzing performance in a Silverlight Line Of Business application, including multiple service layers and he comes across a common problem using ADO.NET Entity Framework including a not so obvious solution.
At the moment we are working on getting out a deliverable to a group of customers as soon as possible. However, one of the issues that keeps coming up is performance. A general response by a lot of developers is to just scour the web for performance tips on different technologies used in the stack and apply as many of them as they possibly can. However I find it much more useful to analyze the problem first.