I have recently taken up multi-sports / triathlons and have been amazed at the amount of times I have thought "I'm going to try those when walking".
This has got me thinking what other gear people used from other sports "crossed over" if you like.
For me the arm warmers cyclists wear are a great idea, I have a set of merino wool arm warmers which I plan to use on my next walk. I am sick an tied of starting to walk in the morning only to stop half an hour later when you have warmed up.