In a few days my family of four will be spending two weeks on the big island Hawaii and hate to buy all our beach gear (towels, chairs, umbrella, snorkel gear etc...) only then to discard it two weeks later. Is there be a company or anyone that will rent these items?
A lot of times we have found the snorkel sets (mask, fins and snorkel) at CostCo, if you are a member. But I'm sure Walmart or Target will have all you need. You would probably end up spending just as much renting as you would buying. Then leave it behind where you are staying. I'm sure they will find a new home. Plus, if you are staying at a resort or even Condo's they will have the towels for you. I would check or have your travel agent check for you.
I don't think they rent towels, but you could always head to walmart there for some cheap ones. Another option is getting those microfiber travel towels before leaving home and then keeping them for the next beach or camping adventure.