Building an interesting and engaging on-line presence is becoming more important for developers, especially if you want to find those cool jobs - or even better have people with cool jobs find you and make you offers of exciting work.
There are a number of aspects to your on-line persona that you should develop, to allow people to find you, understand who you are and also give you a voice within the community.
Common sense stuff
We all like a bit of fun, but unless you dont want to be recognised in public then you should use a good picture of yourself in your profiles. Preferably the same picture in all sites.
Choose one good name / alias
It can be hard to find a good name that people will remember you by, especially when you want to use that name across all the online services (Google, Twitter, etc). Checking that you can get at least a matching twitter id and Internet domain is a good starting point.
Try adding variation to your name to help you find an account name that has not already been taken. I use a zero character in my twitter account (jr0cket) and add a number to my Google account to help me manage a single unique persona. This does mean I am a little more careful with font selection for logos and business cards, etc.
Add a bit of design to your persona
To help make you stand out, get an appealing logo and related graphics that you can use across all the sites you use for your online presence. This helps people recognise you and your work.
Komodo media social media icon pack
Social media icon pack
Collection of free icon packs