как сделать свой Веб-гаджет

Make it easier for people to discover and subscribe to your content
http://www.google.com/webmasters/add.html

Getting Started: Legacy Gadgets API

http://code.google.com/intl/ru/apis/gadgets/docs/legacy/gs.html#GGE

http://code.google.com/intl/ru/

What is Google Mashup Editor?

http://code.google.com/gme/

Google Talk Gadget

http://code.google.com/intl/ru_ALL/apis/talk/talk_gadget.html

Getting Started with Spreadsheets Gadgets

http://code.google.com/intl/ru/apis/spreadsheets/spreadsheet_gadgets.html

Google Visualization API Gadget Gallery

http://code.google.com/intl/ru/apis/visualization/documentation/gadgetgallery.html