MS SharePoint Server 2007 & WSS – Topic for thesis

Currently I am doing a student job as Microsoft Office SharePoint 2007 developer, I am developing web parts and multi task based workflows with info path for a shipping company. I am good in programming, And I have good theoretical Knowledge about it. My background is related to Software Engineering.

So now I have to do my Masters thesis (relating to same work), but problem is I don?t know what a BIG structured topic should I chose (and implement)?

I worked already for 4 months in Microsoft Office SharePoint Server 2007.
I need theoritical/ research topic guidence. Or any oppotunity realted to this