This is probably best bang for buck though not too "classy" looking.

http://www.amazon.com/dp/B002LB7UW2/ref=asc_df_B002LB7UW21959342/?tag=hyprod-20&creative=395021&creativeASIN=B002LB7UW2&linkCode=asn&hvpos=none&hvexid=&hvnetw=g&hvrand=1688479602932333502&hvpone=&hvptwo=&hvqmt=

or the hipster variant

http://www.ecoolgadgets.com/drinkman-hip-flask/