I know that several on this board do not think that these work.... I have found on the whole that they actually do work.  But I think that you have to experiment.  In general most have actives that act much like viagra or Cialis etc.  That is they cause blood vessels in the penus to expand and pool blood.  

Most that contain the bark or extracts from the bark of the yohimba plant seem to work best for me....   If you take them every day - you will notice the effects of them - however they can cause headaches, nasal conjection, some mild stomach upset and other non-life threatening conditions.  So please be careful when using.  You may also wish to take argenine with them as that is the substance that is acted on by the enzymes responsible for the blood vessel dialation.  

They work - I like the effect but YMMV as I have read conflicting reports in the medical literature.  Where to get...  Go to any general nutrition store and look in the "male vitamin" section.  Lots of products in this category.  I like something called "Male Fuel" by Twin Labs.

Re:dick pills

I've noticed that many guy's dicks get bigger when they see me naked. :]

And I'd get some too if I wasn't so embarassed to say "I need some dick pills" at the pharmacy.