I've noticed some really neat shields from some other folks in the Arduino community, so I picked up a few and put them over on the shop page under "Community".
The first one is the ScrewShield, from WingShield Industries. The guys at Wingshield had a brilliant and unconventional perspective on shields: why do shields have to face inward? Thus the "wing-format" shield was born.
Each wing mounts on a row of Arduino headers and extends outwards. The stack-through headers are linked to a corresponding set of screw terminals, allowing wires to be secured to pins (instead of having them fall out of breadboards or the pin headers themselves all the time).
The next one is the WiShield from Asynclabs, which is a compact board carrying an 802.11b WiFi module. I've got my Freedom Kit to talk through XBee and EthernetShield for LAN, but now I can take my Arduino over to Panera and still stay connected to the Internet. It's also got a set of stack-through headers that replicates the Arduino pins, as well as an extra unsoldered row of pins.
Maybe I'm being greedy, but I'm wondering if it's possible to hack a WiShield, EthernetShield, and TouchShield Slide together to make an Open Source, DIY Wireless Router (that also has an interface for readout). It fits together nicely because the WiShield is a little shorter, and doesn't get obstructed by the RJ45 jack on the EthernetShield.
The last one is one I've had for a little while, but didn't have time to try out until now. As the name suggests, the VoiceShield from Spikenzie Labs records and plays back sounds (preferably voices). What I thought was really neat was the fact that the sound could be divided into snippets on specific memory addresses. So each sound can be recalled on command. It's great for those Wall-E type noises when my TankShield scurries across the room and into a wall.
There's also a slot for a 15mm speaker, as well as audio in and audio out jacks. I'm starting to notice a trend with the stack-through pin headers too, and these conveniently provide access to the pins covered up by the shield itself.
Well, that's it for now. I have a couple more on the way, but I'm always looking for new and interesting boards, so feel free to drop me a line if there's something neat I haven't checked out - jhuynh at gmail...