The best way to run ELFs is to buy SwapMagic 3.6 and use the Program Loader on it. If you use this method, all you will need is:
-1 USB Flash Drive
-The Free MCBoot file found below
-Swap Magic 3.6 DVD
1. Unrar the Free MCBoot file, and place contents on root of BLANK flash drive.
2. Boot from Swap Magic DVD, and choose Program Loader from main menu.
3. Choose the Free MCBOOT .ELF File on root of USB Drive
4. Install Free MCBoot when it loads up
I haven't tried this, but if you insert the USB drive before you power on the PlayStation 2, and then boot from SwapMagic, it may automatically boot to the Free MCBoot Installation.

There are a lot of tutorials for these at SKS Apps
Free MCBoot
|
Free_McBootv1.8.rar Size : 562 Kb Type : rar |
uLaunchELF
|
uLaunchELF_v4.40.zip Size : 1224 Kb Type : zip |
PS2Menu
|
ps2mnu-k_v31b.zip Size : 166 Kb Type : zip |
USB Advance
|
USBADVN.zip Size : 458 Kb Type : zip |
HDLoader
|
HDLv7c.ELF Size : 602 Kb Type : ELF |
Exploit Utility/Independence Compiler
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PS2_Exploit_Utility_5.0.zip Size : 1247 Kb Type : zip |