You will get much better advice if you can be more specific about your ideas. Some examples would be helpful. I've built a few gadgets that collect data, analy

You will get much better advice if you can be more specific about your ideas. Some examples would be helpful. I've built a few gadgets that collect data, analyze it, and then send it to a data store on the web. Think carefully about your needs for each of those 3 steps, as well as your readiness to get into low-level technical details. And then tell us more about what you're trying to do. In the mean time, here is some general advice: In my experience, the connection to the web is the most challenging part of the project, and the one that has the most impact on the total cost of parts. Most of the microcontroller kits that appeal to casual developers (such as me) do not include ethernet or wifi connectivity. They assume you will be connecting via USB to a PC. Adding wifi or ethernet to an arduino significantly increases the cost and complexity. For stationary (non-mobile, non-battery-powered) gadgets that need to communicate with the web, I can recommend using a wifi router as a development platform. Many of these can run the OpenWRT version of linux, and collect information from a USB port. Here is a good description of working with linux and USB peripherals on a wifi router: http://mightyohm.com/blog/2008/10/building-a-wifi-radio-part-1-introduction/ http://mightyohm.com/blog/2008/10/building-a-wifi-radio-part... As to cost, the router used in this blog post costs about $30 (http://www.newegg.com/Product/Product.aspx?Item=N82E16833320023 http://www.newegg.com/Product/Product.aspx?Item=N82E16833320...). Another thing to consider is the analysis step. Some devices will have no need for fancy data analysis, but for gadgets that need to work with data in complex ways (learning/compressing/transforming) you may run out of processing power and/or memory on some of the microcontroller platforms. Again, a wifi router is quite capable here - as long as you stick to fixed-point operations. Once you have an idea of a suitable hardware platform, then it's off to the races. There are many great places to see examples of hardware projects, as mentioned by fragmede. And you may want to consider working with a hackerspace (NYCresistor, noisebridge, etc) - I've found that having an oscilloscope is very helpful for troubleshooting my gadget project.