For the latter I would like to point to the latest side-installments of Karabear Comics Unlimited by Ave Messer.
After having, along with a set of other artists and comics, literally gate-crashed this year's 2012 Halloween Cameo Caper by signing up for participation BEFORE the invitation was send out, Ave decided to send the character of Tempore to the party early, by letting him take a VERY round-about trip through time and many of the previous years’ crossover projects, working his way up to 2012…
Tempore, Agent of Order, sets out to get Chaos (of Life & Death nonetheless) but is instead on a merry chase that takes him first to the Halloween Caper of 2006, into the Crossover Wars which he spends most of as a prisoner of the EOU until he is freed and able to visit the Caper of 2007, going straight to the Caper of 2008, then visiting Ringo in The Crossoverlord before plunging onwards again…
It’ll probably take Tempore some time to get to the 2012 Caper unless he gets lost of his way, so do keep an eye on his merry travels until then, he and you might learn a thing or two about Webcomic Crossover History as Ave links them all up.
… have you signed up for the Halloween 2012 Caper by the way? A bunch of artists have already signed up for a trip to the Interdimensional place of Tygris, but there’s still time if you fancy becoming a part of this year’s merry Caper Crossover Project!
Also, Ave Messer is looking for comics and artists who would like to volunteer for a large Webcomic Community Crossover Project. Contact information available through most of the above links, else take a gander at the forum first.