Suggestions for what extras to buy to go with starter kit?

Hi

I've just purchaed an official Arduino Starter Kit for my husband for Xmas. Any suggestions about the extras I could buy to go with it as I really haven't a clue! What are the extra bits that would be good to go with it? I'm guessing it depends upon projects but any advice would be great.

Are there bits I could buy where he could make a sensor (like a vehicle reversing sensor?)

Thanks
Maceyuk

The Arduino Starter Kit comes with lots of stuff, more then enough parts for the 15 projects in the book that comes with it. Along with my kit I purchased "Getting Started with Arduino" this book does an excellent job of introducing the Arduino, it answers the how as well as the what and why. Having worked through this book before starting into the project book definatly made things easier for me. I also purchased some additional RGB LED's because thats where my main interest lies and the kit only includes one.
other then these to items additional accesories would really depend on skill level and interest. as someone who doesn't know Whats what with electronics perhaps a gift certificate to the local hobby shop(the best we've got where I'm at is unfortunatly Radio Shack).

I suggest none.
The Starter Kit comes packed with components. Some of which aren't even used in the Project Book.

The reason I say none is that it's best to work your way through the book first. Build the boards, code the sketches. Understanding the code... projects. Once you have a grasp of the code and functioning of an Arduino board you can decide what components will be useful for you.

I did order another part with my starter kit. A relay switch. I wanted to learn Arduino because I need to build a thermostat for my pond heater. Now that I have the kit and am half way through the book I realised that the relay switch I got isn't suitable for my project. And that's a waste of money.

I just finished the book and I bought a bunch of extra parts that were the same as the included parts. Some of the projects I didn't like that much and others were cool. I would wait until he finishes the kit. Then buy parts to complete projects that he is interested in.

I'm trying to find projects on Google that I think are neat. They have directions on how to complete them and a parts list, so I can just buy my parts based off of that list.