As a 30-something, I've suddenly come to realize that retirement savings are important, and that small amounts of extra savings can add up. Suddenly an extra $100/week actually sounds worth thinking about.
Are there simple ways to earn a few extra bucks as a developer in your spare time? Or is it just down to 'invent some SaaS offering and hope people like it'?
What simple things have you do that have brought in a small bit of extra income?