What's the Difference Between Resistance and Impedance?

I was reading a Facebook discussion today and there was a lot of confusion between resistance and impedance. Someone was trying to measure a speaker with an ohmmeter and didn't understand why his "8 Ohm Speaker" measured less than 8 Ohms. One reply posted this link which I thought was pretty good...

Difference Between Resistance and Impedance

5 Million Raspberry Pi Computers

I read earlier today that the Raspberry Pi Foundation reported than over 5 Million Raspberry Pi computers have now been sold. This number supposedly includes only true sales and does not include the number that have been given away for educational and philanthropic reasons.

Raspberry Pi and Arduino Tech Night

On Thursday, March 5, 2015 the Sangamon Valley Radio Club is hosting a "Show and Tell" evening that will focus on uses of the Arduino and Raspberry Pi single board computers that you've seen mentioned in Amateur Radio and Maker publications. The meeting will be held at 7:00 p.m. The location is:

American Red Cross Building
1045 Outer Park Dr.
Springfield, Illinois 62704-4408

An specific agenda is not yet finalized. There will be a presentation on considerations for applying devices such as these to an application and several SVRC members will be describing and demonstrating experiments they have been working with on their own. If anyone has an Arduino or Raspberry Pi project of your own you are welcome to bring it and share your story as well.

The SVRC will be supplying some light refreshments at the event. As such, if you are not an SVRC member, we ask that you please let us know that you will be coming just so we can get a rough head count.

There is no charge to attend.

If you plan to attend, please send an email to Roger K9LJB at:
president@svrc.org so we can plan for the refreshments.