I agree with the others, my 6m old DD loves her straw sippy and a regular cup (although she doesn't drink, she just gets it in her mouth and 'plays' with it). She probably will never get/like a regular sippy cup.

I got a Nuby straw sippy and she LOVES it! http://www.amazon.com/Nuby-Handle-St.../dp/B000Y2GY40