Playing with temperature sensors on breadboard is cool, but usually, if one has more than one sensor, one likes to get some distance between them.
These are no scientific tests, but in my real world application, LM35 likes shorter cables. The shorter the better, or it will get large fluctuations in measurements.
A cable about 3 meters is as long as I would go. Cable length of 5 meters got me into trouble. Consecutive readings did vary in more than 5 degrees. Not good.
Checked out my local electronics store http://www.oomipood.ee yesterday and got some stuff.
First, a breadboard and some wires. Also got me a soldering iron. Those are just for testing. At least I do not have to twist wires together now.
Then I thought, LED-s are cool for something, right? There is a nice site http://www.ladyada.net/learn/arduino/lesson3.html. So I did get 10 1/4W 1K ohm resistors, and some leds, specifically 2 red, 2 blue and 2 green. 3mm and somewhere near 2000-4000 mcd.