First off, you'll need to split any exisiting video into 10sec segments - there are lots of tools available to do it - just Google video split.
Go to animoto.com and create yourself an account if you haven't already got one. If your video is over 30 seconds long, you'll need to upgrade - thats only $5 a month:-)
Select a seasonal style - there are a few available and import your segments.
The output will wrap a seasonal video around the exisiting one . . .