One of the men responsible for the early successes of Facebook has returned to the company.

[ad#Google Adsense 300×250 in story]In addition to design elements, Aaron Sittig was responsible for one of Facebooks most popular features — photo-tagging. Tagging friends in photos is very popular on the social networking site and allows users to find pictures of themselves and others very easily.

Sittig also designed the icons for the “like” button, photos and wall posts, according to Inside Facebook.

Sittig left Facebook last June to see what else he could do, but decided to return. He explained his decision in an email to NetworkEffect.

I left Facebook last June because I’d been there for five years and wanted to see what else I could apply myself to. I didn’t expect at the time that I’d head back.I spent my time off advising companies and looking for new ideas. But for each idea I wanted to build myself, I kept realizing that Facebook was the only place with the scale and ambition where I could build my ideas successfully.So that, combined with the steady influx of talented people like Sam Lessin and Justin Shaffer, convinced me to say yes when I was approached with an offer to rejoin.