There are tons of citizen science initiatives in the world, but I wanted to highlight a few that are particularly a) cool, and b) relevant to coastal Maine.
Project Noah The premise of Project Noah is to create an online community of amateur naturalists who report their "spottings" via a simple online form that includes the date spotted, location, a photograph, and any additional description or anecdotal information the spotter wishes to share. I have created a profile, and have been uploading spottings from around Hurricane this summer if you'd like to check it out. Project Noah also has a "missions" feature where you cater the spottings for a particular cause.
eBird eBird is an initiative put on by the Cornell Lab of Ornithology (an organization that has created a myriad of other citizen science initiatives as well) that encourages amateur naturalists to submit bird sightings. What is REALLY COOL about the data that you submit is that it helps Cornell create these "occurrence maps" showing different birds movements across the US over the course of the year. Check our this white-throated sparrow occurrence map.
GoBotany GoBotany is a New England online plant field guide which has an incredible database and dichotomous key to help you identify an unfamiliar plant. Within this website there is a feature called plant share, where you can upload and track your plant sightings. To be honest, I am more of a generalist, and prefer Project Noah's easy upload format, but if you are strictly into botany, this is your site.