Along Rio's beaches, there are little stalls where you can get your ice cold beer etc. Beto & Ana are a fantastic couple who will look after you and your things while you swim, walk or play football on the beach. They will introduce you to loads of good people and invite you to join in for a barbecue!
They are on Ipanema, just down from lifeguard tower number 9. Their tent has Beto & Ana written on it. Tell them Anders, Fernando's friend sent you!
Updates
Also try Ordem & Progresso, in front of the Caesar Park - Jorge is in charge, the staff wear t-shirts in the colours of the Brazilian flag. Was back in Rio last week and Beto is now just to the right of lifeguard tower 8. His tent has changed and only carries his name now but the good vibe is still there. He took me to his local cachaca supplier for the last gift home! Wish I could have stayed a month!
Is this your business?