My favorite game to play at a beach is "Spot the Tourist"; it's a very simple game, that doesn't require a lot of skill other than a keen eye. Basically, while lying on the beach or floating in the water, you try to spot any person wearing socks and sandals. Those are tourists and they are 1 point. I could be generalizing, but people wearing socks and sandals to the beach are 60% of the time tourists, all the time. Thus, basic objective to the game is to just spot as many tourists as you can; this game could be played alone or with a group.
Some socks should most definitely be worn with closed-toed shoes though, especially while bicycling. Cycling socks are made from lightweight, breathable fabric to assure that they are comfortable and suited for bicycling. Moosejaw carries a diverse collection of cycling socks for riding your bike, from long cycling socks to short cycling socks, they're all to suit your bike sock fantasies. Most notably, we carry compression cycling socks for bicycling, which will help increase the oxygen flowing through your leg, preventing cramps as you ride. If your friend is a cyclist, seriously get them cycling compression socks as a gift; they'll get over the fact that you got them socks for bicycling as a gift and actually be really grateful deep down, because these socks for your riding your bike rule.
So, if you're a cyclist in need for some great lightweight, breathable socks, Moosejaw has what you need. If you're a puppeteer who makes sock puppets, Moosejaw also has what you need. Whatever you choose to do with your socks for your bike, please just wear them with sandals to the beach. Or, actually wear socks and sandals to the beach because then I get more points.