There are two large web hosting focused conferences currently, they each throw a large event as well as smaller events around the world.
HostingCon has a yearly large event and smaller local events in major US cities. The big even for 2012 is in Boston and I highly recommend it, it is a great place to network. Register using the code “HostingIndustry2012″ for a discount at their site.
World Hosting Days used to focus more on the European markets but has since expanded. Now they offer a show in Germany, Asia, India, and smaller local events. This is also a great one, I attend WHD in Germany last year and was very impressed. Register for the upcoming March meeting using the code “MX14QZ63″ for a discount at their website.