Olympics tickets are still available (provided you have patience with the website and are able to act immediately – there's a lot of love for @2012TicketAlert) but an easier, and cheaper, alternative could be Paralympics tickets.
A record 2.1m tickets to what's often seen as the Olympics' poorer sibling have already gone, offering access to the Olympic stadium and park for as little as £10. At the time of writing there are spaces to see wheelchair basketball players knock seven bells out of each other at the Basketball Arena on 30 August (£15) and plenty of places for sports at the ExCel Centre which include an ExCel Centre day pass (and the chance to get into more sessions). But even more tickets go on sale next week.
Yes, you might not know the names of the athletes, but the same could be said for most of us with many of our gold winners this fortnight. GB's Paralympians are expected to take even more medals than the Olympians (which is why Royal Mail are doing a set of six stamps, instead of one per gold winner) and with stadia packed out the atmosphere will be as good as anything happening now.
Investigate what's available at the official London 2012 ticketing website.