h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Here's one pointed out by STA2 on the Science MBs. It shows how the rubber of a balloon rips round faster than the air can move and thus is responsible for the supersonic bang.
http://members.aol.com/mjbrown/HTML/highspeed.html

Popping a balloon with corn starch shows how the interior air retains its shape. NB There are several photos in the set (some showing interesting petal/leaf remnants of rubber):
http://www.hiviz.com/GALLERY/pasterczyk/cornstarch/cp10r.html
Don't forget to check the rest of the pages too.

More than you could possibly want to know about balloons:
http://www.balloonhq.com/faq/howpop.html

An interesting site with orbit simulations:
http://burtleburtle.net/bob/physics/index.html
among other things:
http://burtleburtle.net/bob/index.html

Dishonesty pays and the media apparently approves:
http://news.bbc.co.uk/1/hi/england/oxfordshire/3576987.stm
(Someone else said they had had trouble finding out what happened next. So I finally bothered to do the search myself.)

This is probably something you should have (and may have) spotted yourself already but I've only just come across it - when someone else linked to it and made a monkey out of themselves.

http://www.dcs.st-and.ac.uk/%7Emorph/

I like the way it's not supposed to be fit for any purpose. With something that accepted 2 images it might be possible to find out what the Rholugx entity looks like.

Very interesting developments...
[Broken link removed by Moderator]
...with rather unfortunate consequences for the shrub-infested areas.

http://www.corante.com/loom/archives/of_stem_cells_and_neanderthals.php

You may have found this listing already but I noticed that at least one of the journals in the chemistry section had some free to view pages so it might be worth checking the others:
http://www.sciencedirect.com/science/journals/chemistry

I thought I'd already posted this one here but when I cam back looking for it I couldn't find it. It was proving very hard to re-locate via google and I still may not have found the original one I saw but it's certainly much the same thing. NB it takes a long time to load before you can play the animation, so not good if you are on dial-up or other inferior or expensive internet service. It is, however, allegedly informative (though rather fast) and quite amazing/funny. It is the origami T-shirt folding instructional video:

http://www.albinoblacksheep.com/flash/fold.php

Patty pointed this story out (on the MBs). There seem to be lots of versions of it online. So in case not all links have equal longevity, here's a relatively sensationalist site (slow loading) and a more sedate one (which also links to the proper journal publishing the article):
http://www.livescience.com/animalworld/050128_monkey_business.html
http://www.bioedonline.org/news/news.cfm?art=1551
(NB There are other good links off each of those too.)

These are quite dynamic chemicals but of all the possible applications of the technology those robotic fish are so Red Dwarf:
http://eap.jpl.nasa.gov/
The video link from within that doesn't work for me but there are other sites with images and the toys may well be on sale somewhere about the plaice ...

There ought to be a big market for animated hands like "Thing" and many other halloween etc novelties.

Lovely nebula picture:
http://antwrp.gsfc.nasa.gov/apod/ap050314.html
(NB first link at top is to a list of archived pictures)

vesicle bioreactors:
http://news.bbc.co.uk/2/hi/science/nature/4104483.stm

pictures of starfish etc:
http://www.seawater.no/fauna/Pigghuder/rodsolstjerne.htm

How to grow your own snowflakes (the high-tech way):
http://www.its.caltech.edu/~atomic/snowcrystals/

I was looking up traffic cones and came across this:
http://www.plasticbag.org/images/extra/traffic_cone_orgy.jpg

Something someone found last year and which I remembered again this year (and had to re-find with Google) when the SpringWatch groupies were talking about various ducks and ducklings:

http://mirror-uk-rb1.gallery.hd.org/_exhibits/bizarre/_more2005/_more06/bad-parenting-mother-duck-leads-ducklings-over-drain-from-which-they-have-to-be-rescued-ANON.jpg

Here are some sites which are probably much more you though than that last one:

http://www.hyperdeath.co.uk/chemicals/ (domain name not really representative of content!)
http://www.nitrogenorder.org/lessons/household.shtml (a US one with the spelling that implies)