My first summer job as a teenager was in the mailroom of a Dublin law-firm. 

The more intellectual duties of this position involved substantial paper-folding, envelope-licking and a daily fight with the franking machine. However, the important part of the job was buzzing around Dublin on my 10-speed bike (with the dropdown handlebars), delivering the mail directly to various law offices and clients and thus eliminating the inevitable delays of the Dublin postal service.