Here is a pic of one of my favorite baby products.  The Nuby Sippy Cup.  Love this thing!  Well built, doesn't leak.  Soft nipple which makes a smooth transition from bottle to sippy cup.  And it fits easily into one of my drawstring purses that I knit.

http://nuby.com/en/nuby/cups-spouts?show=silicone_spouts

http://www.amazon.com/s/ref=nb_sb_ss_i_0_14?url=search-alias%3Dbaby-products&field-keywords=nuby+sippy+cup&sprefix=nuby+sippy+cup

These links ought to get you started!