It's nice to see this thread revived. I've slowed down on upgrading/modding since I first posted this thread. After all, I don't want to burn a hole in my wallet. This is what i've done since my first post (I may be double posting, please forgive me if I do):
->Added a red LED fan (mainly for looks) on a side "vent" of my PC's chassis. This is where my hard drive used to be when I first bought my machine (an HP, HPE-400f, a rather budgety consumer model PC [$850 with stock components]) I have my stock fan stashed in a box somewhere in case my newer fan breaks. Since there are no screwholes on the side of my machine (BTW, my PC was NOT designed for modding, it's a consumer model. Had to use some creativity for this tweak.) I'm holding up my fan by a couple pieces of duct tape. Go ahead, laugh. So far, it has yet to peel off.
->Purchased a NexStar 3 external hard drive case. This is where my 1 TB stock hard drive resides now, and i'm mainly using for backups/fault tolerance.
->Removed my SATA III add-in card. Since I don't have a SATA III SSD yet (and not for a while), there isn't a need to waste the additional power to run it. Still using my MOBO's SATA II ports for peripheral connections.
->Installed a 550W power supply. Replacing the PSU was not much fun, but I was able to pull it off successfully and all devices and peripherals work just fine. MY BSOD problems went away after installing the new PSU, so I was overpowering my machine (the HPE-400f comes with a measly 300W PSU stock).
->Installed a green cold cathode light (I may of mentioned this already). Since my PCI-e slots were all taken at the time, I had to kink out a mini-PCI-e slot which has no connectors to the mobo. The PCI bracket switch was on the inside of my machine due to lack of space, and it became really irritating to open up the side of my machine every time to turn the cathode on and off. So I duct-taped (from the inside) the PCI bracket switch onto the mini-PCI-e slot. It looks pretty bad, but at least I can turn on/off the cathode without opening up the machine anymore. Like with the fan, the tape has yet to peel off.
It seems that i'm the only "modder" so far who has ever used tape on the inside of the machine. I wouldn't recommend it to anybody, unless if you want to be REALLY creative and go beyond typical screwholes for mounting. But tape isn't very sturdy. And it looks HORRENDOUS if placed on the outside (especially the front). On the bright side, my machine is pretty spacious on the inside to accommodate all of these mods (it's a mid-ATX form factor tower). And the best part, none of the wires are hitting against any fans, touching RAM/other hot parts, etc.
Next time I get a PC, i'm gonna try to build one myself.
There's just only so much you can do with a consumer model PC, which was not meant to be modded.