Wearable devices, or “wearables” for short, have enormous potential for uses in health and fitness, navigation, social networking, commerce, and media. Imagine video games that happen in real space. Or glasses that remind you of your colleague’s name that you really should know. Or paying for a coffee at Starbucks with your watch instead of your phone. Wearables will transform our lives in numerous ways, trivial and substantial, that we are just starting to imagine.

In a new Forrester report out today, we argue that wearables will move mainstream once they get serious investment from the “big five” platforms — Apple, Google, Microsoft, Amazon, and Facebook — and their developer communities, and we give advice to product strategists who want to stay ahead of the wearables curve. Key takeaways: