Go for a power supply with Active PFC. Power Factor Correction (PFC) allows power distribution to operate at its maximum efficiency. For more information see Active PFC FAQ
i use outlook for its calendar and scheduling. If it didn't have that i would use Thunderbird. I say lets merge Sunbird and Thunderbird together to kill outlook as well as IE!!!
this means you can use your ide hard disk. SATA is way better than IDE (150Mbit/s vs 130Mbit/s) and will only getter better with SATA2. As for the fan connections see if the asus site lets u view the manual for the motherboard, it will tell you.
go to www.lvllord.de to get a fix that u can set the number of half-connections open at any one time. Default is 50 and should be enough to still stop worms propogating but still stop you from getting this warning.
google your download speed problem because you aren't the first to ask such a question. It basically comes down to stuff to do with the TCP/IP protocol (can't remember exactly what though)
Firefox is the only way to go, much faster especially with the "Tweak Network Settings" extension. IE only beats it in the initial load since its integrated with explorer.exe
also look at how many titles on the gamecube are sequels from previous platforms. Where did the awesome orginality that we know and love from Nintendo go??