Hi everybody i'm new to this forum and to arduino !!!!! I have a super newbie question but can't find the answer in the forum. Is it possible to do morer than one project with the arduino board ????? I mean do we need to solder the board when you have a big project or you never need to solder the arduino board so you can use it for multiple project...Because right now I have a breadboard to paracticeBut I want to know if you to solder your arduino board for a project ????
Thanx in advance Ben
The Arduino is a prototyping platform. When finalizing a project, most people will build a "standalone arduino" or "breadboard arduino" (both are search terms you can use.)
It is your choice if you want just the bare minimum components or an actual Arduino board. There are no rules.
thanx so if i understand correctly when you solder on the arduino board this one is over for other projects....
thanx Ben
The real answer is, it depends. The idea behind a "rapid prototype" device is something you don't solder directly to. (Personally, I'm not sure what you would solder to. Unless you went through the trouble of removing the I/O sockets. Which is probably a good chunk of work in itself.)
You might consider getting something like a "Proto Shield" so you can solder on that. It will keep your (relatively) more expensive Arduino available for future projects.
Or do like I do - develop/debug the project using something like a deumilanove, then program the code into a promini (or one of the similar boards) and build that into the final project.
Here's a promini being built into a remote LED display. I hot glue it in place once the wiring is done & it is checked out.
Excellent question! I just found out about Arduino two days ago and ever since I have been browsing and gathering info for about 20 hours already.
I wanted to know this same info. Not because of cheap but because I am located at Costa Rica and it seems that these boards are not available in my country. I have to order them on Amazon and have them shipped to a PO Box and where it will be forwarded to me. This whole process takes about an extra week and a half and at least 12 dollars for shipping and handling plus customs taxes.
So if I have to buy a board for each project it's not that fun to get started.
There are no rules.
Well, there are a few, concerning things like current draw, maximum memory, speed etc, 
Benoit-1842, Sket2Cr
None of the answers you received mentions a solderless breadboard. You buy a solderless breadboardn(about 390 point in your case), and a wire spool from Radio Shack (solid, not stranded), and create some jumper wires. The Arduino board has i/o connectors that accept jumper wires. There is nothing to solder. That way, you can use both boards over and over. Another solution is a protoshield; most of them have a solderless breadboard on them, albeit fairly small.
amcduino