I play this song all over the neck!

Seriously, it's the same chords over and over and over...unless you modulate...and I find it easy to stick in all those Hendrix/SRV blues and pentatonic licks.
Also, I tweak the chords just a little. Instead of playing straight major or minor chords, I play a couple compound chords and chords with modifiers, like this:
Open the floodgates of heaven
C - - - - - - - - - - - - - -G/B
Let - it - rain
Em - G - Am7
Let - - it - - - - rain
Am7 - Am7/G - Fmaj7
It's a great song to practice chord inversions on, especially over the C, G, Am and F chords since it holds each one for a few beats. Give time to mess around a little.
Maybe I'll do a video of this one?