Where do you keep your InfoPath forms? Are they in SharePoint or on a network/local drive?
You could generate reports from InfoPath using code but it would be a lot of work, also, the report would by nature be custom to a single InfoPath template and not a "generic" solution.
If your forms are stored in SharePoint there is some limited reporting you can do from SharePoint (export to Excel) but that won't work for repeating data in your InfoPath forms
We do offer an easy to use tool that is used for InfoPath reporting called "DBXL". It comes in client or server editions.
Here is some info about DBXL that will explain the product: http://www.qdabra.com/en/products/DBXL.aspx and this demo video http://www.screencast.com/users/qdabra/folders/Default/media/46fa1700-c3a8-4696-93c0-4e3cf03703b7 shows you DBXL reporting out of SQL vs reporting out of SharePoint.
Hope that helps
Ted