GPS and WiFi combination

Being interested in GPS topics, I've spent a few hours on Internet reading about the current available solutions. As I was browsing the pages, I've came across the Description of positioning systems. My curiosity has been directed towards Skyhook Wireless' Navizon - a software solution that allows mobile devices to access online database of positions of WiFi access points around urban areas of cities. For a mobile WiFi enabled device that is able to capture MAC of any access point, it becomes a matter of pointing down a known location of that device on a map stored locally. New maps can be uploaded to Skyhook's server updating the locations of moved APs. Likewise, maps can be easily downloaded to a portable device, allowing offline browsing.
In the absence of APs, GPS locator can take the lead. On the other hand, when GPS signal is low (places like buildings, tunnels), WiFi will kick in. The best part about it is that there is no need for Internet connection - MAC addresses are transmitted by APs for free!

In my understanding this is a great solution, providing the following:

• Maps can be downloaded whenever one has an Internet connection
• MAC broadcasting feature of APs can be exploited to determine one's position
• Can be combined with GPS receiver (use software to switch between WiFi and GPS)
• GPRS can be used whenever one cannot download maps via WiFi (i.e not available)
• Central database is updated by thousands of users automatically

One thing that is interesting to mention is the following. If a location of MAC address of some bogus device that is constantly moved around the city is uploaded to a server, it might create confusion because it can be detected by a mobile device in a different location and create the wrong sense of position, especially if it's the only or one of few APs around the area. Now, of course the software should be smart enough to detect the change and warn the user of inconsistency. All the user have to do is move and discover more APs.

Related:

RF Fingerprinting in Wi-Fi Location Tracking

Hardware projects

Dev/Project related
Dev board with a microcontroller

Gadgets, ideas, DIY electronics links
OpenSource gift guide
The Time Fountain (really cool fountain project, which uses strobe light to "freeze" or slowdown and reverse the motion of fluorescent drops).
Lucid Dreaming Mask (by the author of The Time Fountain. He claims his inexpensive hardware triggers lucid dreams... thought I might add this here since I've spent some time reading the experiment).
Hacking Roomba robotic vacuum cleaner

Photoshop classics

Some cool photoshopped classics:

Coffee, Reach, McDavid, Raid

Inexpensive Arduino microcontroller dev/project board

Parallax’s Basic Stamp is the mainstay for hobbyists wanting to add intelligence to everyday devices. A new system called Arduino provides the benefits of the Basic Stamp at a greatly reduced cost, increased speed, and is entirely open-source. (http://todbot.com/blog/2006/09/25/arduino-the-basic-stamp-killer/#more-121)

Mobile Processing

Mobile Processing is an open source programming environment for people who want to design and prototype software for mobile phones. It is based on and shares the same design goals as the open source Processing project. Sketches programmed using Mobile Processing run on Java Powered mobile devices. (http://mobile.processing.org/index.php)

Configurable Processors

In this article, Steven Leibson from Tensilica shows some tricks used to hardware-optimize DSP computations with the help of SoC, FGPA, or ASIC. He emphasizes that the use of hardware acceleration is crucial for many DSP applications. Adding special instruction extensions supported by configurable hardware has advantage over assembly-code optimization of a critical path of an algorithm.

There are a few examples (MPEG4, Viterbi and FFT).

http://www.dspdesignline.com/howto/showArticle.jhtml?articleId=193302782&pgno=1