Where's the love fellas? <group hug>
For the original poster:
Some search topics to help you:
TVT 250 kit
NeedsWings CAI (cold air intake)
ECU tune
Those are the three biggest (and most readily available) things you can do for a normally aspirated Crossfire. I do want to mention though, that the TVT 250 kit includes ECU tune and CAI (as well as injectors). So don't go backwards up my list.
Some other less popular alternatives include swapping in a Mercedes V8. But if you're anything like me, that's beyond my mechanical ability and the power of my check book. Search for a thread started by LantanaTX for the story of his V8 install.
Exhaust mods are available too, but they offer relatively poor bang-for-the-buck as far as performance goes. Most folks get them for the sound rather than any performance aspect.
Lastly, I'll mention that TVT_Design is pretty much the king of the NA Crossfire mods. He's one stop shopping for most everything. There are other vendors and other products, but Anthony at TVT will set you straight. Most of the other mod shops focus on the SRT-6 and performance mods unique to it, which won't help you much. Regardless, Rob @ NeedsWings is a great guy and will help you out any way he can.