Being physically surrounded by like-minded developers (in an office) exposes you to these convection currents. You can't help overhearing John talking about the new API he discovered, or Sarah arguing with Mike about which Pattern would best solve problem X. When you work from home all you get is silence.
The great thing about these currents is that they are usually exciting, challenge you to change the status quo and stop you resting on your existing methodologies. It can be difficult to keep your saw sharpened if you lack day-to-day peer interactions.
I recently upgraded my phone to a cool new Windows Mobile device. The inbuilt RSS hub is now full with dozens of blog- and podcast-subscriptions that I can access anywhere, anytime. This is revelationary! Today I read Joel's post: 12 Steps to Better Code whilst out in the garden with the dog. Fantastic. And so little effort involved! I am no longer required to be at my desk if I want to learn.
And that really is the key: I needed a no-brain, easy solution to keep in touch with my peers and what they are doing today.
Just because you work remotely doesn't mean you can't be part of the conversation.