Thank you for this great answer.
They have their own reasons for not having a fan club. You can get access to presales for local shows by joining their mailing list. If you want to go to something farther away, you can always post here asking about presales. As far as meet'n'greets, they also have their own reason for not selling those or backstage passes like other bands do(lol and people say the Offspring are sellouts :P At The Used concerts, you have to buy a cd to get into the post show "meet'n'greet" which is really just an autograph session). If you pay attention to the radio and even get in touch with people in your area from the BBS, that is your best way to get into a pre/post show meet'n'greet. Not all shows have them though. I went to a festival on Sunday and there wasn't one. There was a "Enter your name in a hat and meet them briefly pre-show through the radio station" meet'n'greet, but I guess because of the size of the venue and other factors, there wasn't one after the show. They even had the buses blocked off, which I haven't seen at an Offspring show before. That is the other way to meet them. Usually, people will wait by the buses after the show. We tried to do that Sunday, but the buses were in a restricted area surrounded by security. Did it the last time they came through, but their tour manager came out and told us they didn't have time to come out and meet the 15 or so people that were waiting. He was super nice though.
Fan clubs don't bring us closer to the bands. These guys work really hard to stay in touch with their big time fans. You'll find if you pay attention, meeting them and bonus stuff isn't as hard to come by as it is with most bands.
Noodles posts under the accout "Noodles" with the user title "Band member". He is also a big fan of Twitter.