I'm told freezing them after cutting the tops off is good. My friend (who is Latino and eats tons of salsa if it matters) and his mom do that.
Pickling is a classic way to preserve vegetables. Shove them in salt water and get a water seal and the acid from the lactobacillus will prevent nasty bugs from contaminating them.
I've not tried either with peppers though so can't offer first hand advice.
I either make hot sauce or pickle my jalapenos every fall - slice em and simmer them briefly in vinegar, salt, sugar, garlic solution, great on burgers, hot dogs, nachos, etc. especially good in corn bread