If your EVO is rooted, running a 2.2 Sense or CyanogenMod ROM, and has either ClockworkMod 188.8.131.52 or Amon RA 1.8.0 (custom recovery images) installed, then you can flash any of the 77 font packs that xda-developers' fachadick has packaged in convenient .zip files for us.
You already know how to flash a .zip, so the "hard" part is simply deciding which font you want. Each pack only changes the system font, so you can flash as many as you want (one on top of the other) until you find the one you like.
The stock font on the EVO is called DroidSans, so you can always go back to what you had before if you end up not liking any of the other fonts; you could also do a Nandroid backup before flashing the fonts and then restore the backup if you want to go back. Not all fonts are created equally and fachadick says that some could slow down your ROM and/or web browser, so keep that in mind while you're experimenting.
That's the Sony Sketch font you're looking at above. You can see screenshots from fachadick's blog of the Kudasai and Calvin & Hobbes fonts below, and of course you can check out all the fonts on your own EVO by visiting the xda-developers thread at the link beneath the pics.