During my current Lotus to SharePoint migration the mail concern was the migration approach and cost associated with it . There were 2 options :
1)Either create a migration tool as per requirement which means a good number of Person Hours
2)Second approach is to buy a third party tool ,but in this case as there arevery few lotus application to be migrated and that too they were simple ones so buying a tool was not a right decision and was not even good fit for budgetting of the project .
After lots of research i got the "Microsoft Application Transporter 2006 for Lotus Domino" from Microsoft .Download from " http://www.microsoft.com/downloads/details.aspx?FamilyID=c6066e89-7690-44a4-86d6-ab1d60808022&DisplayLang=en"
Now this fits to our requirment and i must say that tool is good enough for simple and average complexity Lotus notes application migration