1. You can display iView within SPS web part with the iView web part tool kit.

Link to the article http://www.infoworld.com/article/04/08/09/HNwebpart_1.html

Here’s the workspace on gotdotnet

http://www.gotdotnet.com/Community/Workspaces/Workspace.aspx?id=d6129dc0-efc4-457d-a821-fd26aef566de

2. You can setup SAP ITS, to display SAP GUI in SPS Page Viewer Web Part, like this:

3. Microsoft had developed two sample SPS web parts which call SAP web service developed by using .NET connector, to display data from SAP.