Hi thebigG,
Welcome to InfoPathDev.
Are you attempting to filter out a dropdown control based on the current user? If so, then yes this is doable, the only problem you would be facing is the limitation of what you can query from SharePoint. May I know how you are categorizing the dropdown for each user?
What I have in mind is arranging the items in SharePoint to have a column that determines who the current item is for (example: Set A, B, C, D, E, etc...), then the user should have a group, and I was thinking of using the Active Directory to deterimnethe current user's department. If not, you could create a new list and add in all the users together with the group they belong to (example: Group 1,2,3,4, etc...). If you already have this kind of setup, you can add a field called CurrentGroup and then filter out your dropdown control based on the current user's group. I hope this makes sense.
Regards,