creating a profile photo using file upload

I just created a profile page were users can enter their name, current location, age, etc. I want users' profile info to be created together with their profile photo on the top left hand corner. I've created a database for the profile but I will need help on how to开发者_高级运维 upload a profile pic using either file upload or any other method.

Consider using Gravatar. That's what StackOverflow does.