All of the activities that are eligible for the Summer Challenge will be on our site after the Challenge ends on August 31st, with the small exception that we will remove activities slipped past our editors and that just don't work well or for some reason become obsolete. Additionally, there will be a lot more added each week.
Education.com will not "forget" which activities you have done and logged as a part of the summer challenge, but we do not yet have a page that will list all of your completed activities after the Challenge ends and and the Challenge-specific page disappears. Perhaps by August 31st we will have created such a page, and then you can keep a running log of your activities even if there is no Challenge active.
I strongly recommend that, if you have a digital camera, you take pictures of the activities that you do and keep these photos. There may be a way to share them with others on education.com later this year.