I am a .NET developer. I started getting fit by walking to work - about 2 miles each way. That burned off 40# in about 9 months.
For fitness, I currently dance: Zumba, U-Jam (think Zumba but with hip-hop) and belly dancing. For balance and flexibility, I tend to stick to yoga/pilates type classes such as "BodyFlow" and "Willpower and Grace".