A simple design project for font lovers: Single-character typographic coasters.

• Invisible gecko
• Nice vehicle concepts by Luigi Colani.
• Contraptor, another interesting open source hardware construction system
• How trees shed leaves
• Geometric fractals in Processing
• Oloid, a geometric toy
• Lucky cat candy
• I wish I had an RC submarine to use one of these.
• Frosty Bubbles
• A Commodore 64 emulator written in LabVIEW (via @Paeaetech)
• Did you know about the Secret Single-app Mode in Mac OS X?
• Interesting construction accident. [Snopes link; beware of popups]
• Nice sunset
• Soda bottle rockets at Popular Mechanics
• Roundup of geek cufflinks
• I could watch slow motion bullet impacts all day long.
• DIY motors for electric airplanes
• Average Cats

Okay, maybe that's a bit of an exaggeration. But, the deadline for our Arduino Contest at Instructables is approaching right fast: Entries are accepted until this Sunday, Nov 15, 2009, at 11:59 PM PST.

Why enter? To show off your cool stuff! Also, you could win a Meggy Jr RGB handheld gaming kit, or an Arduino Mega or other nice goodies, so don't you want to come out and play?

Official contest rules are here. The basic entry requirement is that you make a project that involves the Arduino IDE in some way, and you can already check out many of the great projects entered. Woo!

We've picked up a bunch of improvements on our Edge-Lit Holiday Cards since last year and we've collected them here for you to see. (Also, welcome Popular Science readers! This project is mentioned in the December 2009 issue.)

One of our first kit projects, and one of the consistently most popular, has been the LED Mini Menorah project. For a couple years now we have meant to revisit that project, and we've finally got around to doing so. Here is the result: our new Deluxe LED Menorah Kit.

Our automatic ice maker is on the fritz, so we've temporarily reverted to making ice in conventional trays. But, imagine our delight at opening up the freezer and finding this!

Several of our ice cubes apparently formed with long spikes on top. This is really *not* what you expect when you start out with liquid water in an ice cube tray.

Snowcrystals.com has a fairly detailed explanation of how these things form, and it's documented elsewhere as well. (Roughly speaking, supercooled water is pushed up through a hole, somewhat like magma forming a volcano.) It's relatively easy to form these in your freezer if you start with distilled water, but occasionally-- as in our case --they do occur with regular tap water.

We've seen a lot of great Arduino Halloween projects out there this year. A few of them have been submitted to our Arduino contest over at Instructables, and we'd love to see more. The entry deadline is Nov. 15, so you've still got time to send them in.

Speaking of contests, the Make Halloween contest deadline is here. Quick, get those microcontroller projects entered before midnight on Nov. 3!

Here is how to make your own cast concrete tombstones. These are easy, inexpensive, impressive and tough Halloween props, ready to spook in 24 hours.

Lately we have been working on a new version of the PeggyDraw program, which is a program that lets you draw things that you want to display on the Peggy 2 for static images. The new version isn't quite ready to show off this week, which is too bad because we like to put out our Peggies for halloween.

On the bright side, Mark Delp just sent in a program called bmp2peg that's been added to the Peggy project at Google Code. It converts a (tiny) windows BMP file and generates an Arduino sketch that can run on the Peggy. (bmp2peg runs on windows, and also on linux if you recompile it, macs unknown thus far.) Both bmp2peg and the original cross-platform PeggyDraw can be used to put static images on the Peggy, or to generate static frames that you swap out in the code to build simple animations. The window-friendly pumpkin above was drawn as an image file, converted with bmp2peg, and installed on a Peggy 2 filled with orange LEDs.

Last year at halloween we took a different approach to the Peggy in the window. We took one filled with red LEDs, and every twenty seconds (or so) it would flash the letters "BOO" -- huge and bright -- and then go dark again. We took a little movie of this last year, showing how that works.

(The flickr video is embedded below -- if you can't see it, click through to see it.)

The video is very dark, but it's accurate: our street really is that dark on Halloween. You have to walk slowly because you can't see where the sidewalk is.

• Music of the long now
• Nesting Eyeballs
• Garlic Bread Dalek
• Another Dice Bag
• A good introduction to using solderless breadboards for electronics.
• Silly swirled frosting for cupcakes
• Yet more silly happy face math.
• Comic bok book grammar
• Penrose floor tiles, with links to more.
• Make a drinking straw cruise missile
• "Building blocks" of lego robots
• Creepy soft sculptures by Melissa Sue Stanley
• The Prime Spiral
• Throbbing Oil
• Old school trick for making repeating tiled patterns.