If you're in Mazatlan, be sure to check out the zip line canopy tour from Huana Coa!  It is well worth the $75/USD.  The bus picks you up right in front of your hotel (and drops you off again when it is over).  It is about a 20-30 minute ride out of town, on an agave plantation.

The guides - Chino and Omar - were fantastic.  Both spoke English very well and wanted to make sure everyone had a great experience, but kept safety in mind.  The harness and other equipment was first-rate.  There was even a photographer available (for an extra $25) that took almost 100 photos and had it ready in less than 10 minutes.  The zip line consisted of 9 lines (with the last two actually going from one tree to another).

After the zip line you are were given a tour of the tequila factory - Vinata Los Osuna - with all the samples you can drink.  Bottles of the boutique blue agave are available for purchase at around $35/USD.  There is also a small market next door if you want to purchase souveniers (hammock, wood carvings, jewelry).