InfoPath Dev

If I have a List with two columns, Name and Phone Number. Then I created a new list where I have Names in a dropdown being pulled from the first List. I want to autopopulate Phone Number on my NewForm.aspx based upon my selection, I jsut can't figure out how. 

I think what you're looking for is cascading dropdowns, which is very possible in an InfoPath form, but it sounds like your question does not involve InfoPath. I don't know whether cascading dropdowns are available out of the box on SharePoint lists. Some info here, here and here. Good luck!

Yes, I am trying to accomplish in InfoPath 2010.

I have 2 list... List A = Route, Mileage (calculated based on Route) and Zone(calculated based on Mileage). 

List B - Route (Lookup from List A).

On my NewForm.aspx (in InfoPath 2010) for List B I have the Route dropdown list which is working.  I then need to be able to do something like if ListB Route = ListA Route, display ListB Mileage......  on the form in a non-editable table cell.

Got it!!!!!   If I had only known what to look for before. I knew it had something to do with the Rules and Filters!

http://www.petestilgoe.com/2010/04/how-to-autopopulate-infopath-fields-using-sharepoint-list-data/