It's not too late unless you're otherwise engaged. There are still seats being made available. I managed to get seats for tomorrow's basketball on Sunday, and there were many others that popped up last night, allegedly the first seats returned in the current reallocation effort. There seems to be a statement that a last cut of tickets for each event will appear the night before.

I think many, like me, just want to get on to the main site. So basketball, handball and water polo are harder to get than volleyball, weightlifting and boxing (other sites). But beach volleyball is doing well ... still hoping to find something for tomorrow evening.

This site will monitor a shortlist and alert you of any availability (though I've only tried it today): http://checker.benmarshinteractive.com . It probably helps though if you are already signed-up and logged-in to the LOCOG website, and have made a dummy purchase.