I'm doing research on the technology behind talking greeting cards.
Here's a link to an article of interest:
http://popularmechanics.com/science/time_machine/2002/5/talking_greeting/
A key quote from the article is "a battery-powered microchip with tiny
speakers is attached to the card". I need to find more information
about and a source for the microchip with and/or without the speakers.
Also please list any other options you find for recording voice in a
tiny device. Another link of interest is here:
http://www.eurocosm.com/Application/Products/Tcards/tcard1GB.asp I'm
not sure of the technology behind these cards though. TIA.

Hi! Thanks for the very interesting question.

If you want to have background information for these types of
microchips the following documents would be of help to you.

“NEWLY PATENTED APPLICATION FOR VOICE CHIP ENABLES TALKING PRODUCTS
AND APPLIANCES THAT SHARE MESSAGES”
http://www.voice-express.com/ptop_patent.html 

“Kit 64. 90/120 Second Message Recorder”
http://www.ozitronics.com/docs/k64.pdf 

ISD5008 (The chip itself)
http://www.winbond-usa.com/products/isd_products/chipcorder/productbriefs/5008-pb.pdf

This link provides a rather in-depth discussion of the technology with
one particular type of voice recorder product called the ISD/Winbond
ChipCorder.

“ISD/Winbond ChipCorder Frequently Asked Questions (FAQ) List”
http://www.winbond-usa.com/products/isd_products/chipcorder/faq/FAQs.pdf

For the techies in your group, this schematic diagram I found could
come in handy someday.

Single Chip Voice Recording / Playback Device
http://www.qsl.net/vu2upx/Projects/APR9600.htm

In case you have a business in mind for these types of chips, this
product catalog from Everlite would be a great place to generate some
ideas.

“Everlite - Digital Voice Recording Products”
http://www.evergroup.com.hk/everlite_voice.htm#v220222 

The Messagebay website has a novel idea wherein you could record a
message over the Internet then embed it on such things like greeting
cards.

“MessageBay and Voice-Express Embed Voice into Personal Talking Cards
Record Your Voice Online, Delivered With a Physical Gift or Promotion"
http://www.messagebay.com/press/2000-10-25.php 

Whenever you need voice recording microchips, you could get such
products from the following vendors:

Voice Express Products
http://www.voice-express.com/cgi-bin/ePages.storefront/264896964/Catalog/28625-28632

Voice Express for Greeting Cards
http://www.voice-express.com/cgi-bin/ePages.storefront/264896964/Product/View/28625-469500

http://www.voice-express.com/cgi-bin/ePages.storefront/264896964/Product/View/28625-887342

Winbound: Chipcorder
http://www.winbond.com/e-winbondhtm/partner/b_2_a_4.htm

Quasar Electronics
http://www.quasarelectronics.com/sound_recorders.htm 

Eagle Systems
http://eagle-systems.net/products.htm

Search terms used: 
voice recording chip "greeting cards" technology

I hope these links would help you in your research. Before rating this
answer, please ask for a clarification if you have a question or if
you would need further information.

Thanks for visiting us. 

Regards, 
Easterangel-ga
Google Answers Researcher

great research. thanks