🚀 go-pugleaf

>Pin 5 (control voltage) generally gets connected to a 0.1 or 0.01 uF

As previously stated, pin 5 can be used to alter the output frequency.
One circuit that I recall was to have the output of another 555 timer 
connected to pin #5  (one variation was to have the output go through
an RC ie: pin #3 (ic2) connects to Pin #5 (ic1), with a cap at pin
#5 (ic1) to ground or power.  This will give you a siren or whooping
sound depending  upon the values of resistors used.

>The equation for a 555 running in free-running mode (from the Radio
>Shack Semiconductor Reference Manual) is:

Be very careful with equations: I've seen different equations for 555's,
duty cycles, frequencies, etc. depending upon the manufacturer. 
Also, some will work even after pin 7 is shorted to pin 8, others
will blow out immediately if the resistance is lower than 1k or 200 ohms.