I covered Walnut Creek's last Downtown Wine Walk here, but if you need more information or are too lazy to click on that link, here's a refresher.
First, even if you don't plan on attending it's always good to remember the event is going on, if only to understand that traffic will be slow throughout downtown Walnut Creek as parental-looking types meander in and out of stores with wine glasses in hand.
Secondly, if you've never been, this is how it works: You start at Pro Home Systems, either to pickup or purchase tickets (tip: bring cash to breeze through the line). Organizers will outfit you with a map of participating businesses (this time around there are over 45) and a souvenir wine glass, and then it's up to you to plot a way to hit as many local businesses as possible, all of which are pouring varying varietals from different wineries. Many also offer food, in the form of cheese and crackers spreads, but some places get real fancy with chocolate fountains (the post office store really did it up in spring).
It really is a pretty good time if you don't mind bumping into numerous people from high school and college, feel no obligation to pretend to be interested in whatever the store is selling, and don't lose patience in crowds and lines. For $35 you could do worse than have potentially over 45 tastes of wine. That's 15 businesses an hour, which works out to about 2.7 bottles of wine over the night (assuming 2oz pours). Not too shabby...
Presale is closed, but you can buy tickets at Pro Home Systems before the event