looking at literally EVERY arduino project on Make, instructables and hacknmod to see which project that i want to replicate
Just a minor caution for you here. These sites have a ton of very useful information on them, but as with virtually all open sites on the internet, that useful information is somewhat diluted by, to put it mildly, less than useful information.
To put it less mildly, I've seen numerous projects on some sites that contain absolutely horrible examples of source code. You appear to be going down the right path of actually learning how to program your Arduino, and you should continue to commit yourself to that path. I've seen too many people just take code from these sites, mash it all together, then come here wondering why nothing works.
My one recommendation, never use any code that you do not understand. That means knowing how to program C/C++. I've seen several sources make this claim that you don't need to know how to program, and to be blunt, that is complete hogwash.
The reality is, if you don't know how to program, the only things you'll be able to do with your Arduino are replicate existing well documented projects with little to no modification, and even that will be a challenge as you won't have the necessary skillsets to properly diagnose and debug any issues you run into while replicating that project.
Am i limited to projects because i only have a arduino uno? Im sometimes disappointed when tutorials use an ardweeny or a duelimaneuve(sp?) in their projects because i dont know if an arduino uno is interchangeable or not.
Anything you can do with an ardweeny or duemillanove, you can do with an Uno. With regards to the Duemillanove, the Uno is a direct drop in replacement. With regards to the ardweeny, I'm not familiar with it's layout, but functionally speaking the Uno will be just as capable. There may be some differences in pinout/wiring though.
Anyone here have any suggestions on what is a good first project that is a bit challenging?
As a starting point, you have the existing Arduino examples. Don't just compile and run them, but focus on understanding the actual code itself. Then try to recreate the examples from scratch, without just copying the existing code. The recreations do not have to be exactly the same, you can introduce some changes of your own devising, but don't get too carried away, try to stick with changes you're sure you understand how to make.
If you have some funds available, another option is: http://www.sparkfun.com/products/10173
This kit provides a variety of useful components with an Arduino, and a booklet of projects that show you how to build circuits with those components and write code to work with those circuits. That booklet is a freely available download as well (link on that product page). So go ahead and download it, read through it, perhaps run any projects you currently have the components for. Should give you a good idea if it's a kit you'd like to purchase. Even if it isn't, the booklet is still a good source of additional projects to work. It's just up to you to provide the necessary components.
