Thanks for posting the pictures and letters on Spring Tails. Similar to one of your readers we saw these little guys on Christmas day in Oregon and have been stumped for a month trying to determine what they are. Here are two more pictures we took that you can publish. The Douglas fir needle gives you a little bit of scale.
We are glad to hear our site assisted you in the identification of your Snow Fleas, a type of Springtail that can be very plentiful on warm winter days.