Joining three lines with comma separation

I have a file that looks like this:

G. KRESSLAR
9618 W. APPALOOSA DRIVE
SUN CITY, AZ 85373
SHIRLEY ALLEN
7272 W. VIA MONTOYA DRIVE
GLENDALE, AZ 85310
LOUIS VALDEZ
244441 N. 86TH AVENUE
PEORIA, AZ 85383
DONNA NEWBON
3231 W. DENTON #D
PHOENIX, AZ 85017
SARAH WILSON
6534 W. PALO VERDE
GLENDALE, AZ 85302
W. GRISAMORE
10017 W. PALMER
SUN CITY, AZ 85351

What I need to do is join each set of three lines, separated by a comma, so that it looks like this:

G. KRESSLAR, 9618 W. APPALOOSA DRIVE, SUN CITY, AZ 85373
SHIRLEY ALLEN, 7272 W. VIA MONTOYA DRIVE, GLENDALE, AZ 85310
LOUIS VALDEZ, 244441 N. 86TH AVENUE, PEORIA, AZ 85383
DONNA NEWBON, 3231 W. DENTON #D, PHOENIX, AZ 85017
SARAH WILSON, 6534 W. PALO VERDE, GLENDALE, AZ 85302
W. GRISAMORE, 10017 W. PALMER, SUN CITY, AZ 85351

Is there a simple sed or awk solution to this?

Thanks in advance for your help.

I tried this and it appears to work.

sed 'N;N;s/\n/, /g' < in-file > new-file

Am checking now.

I also need to include double quotes around each input line so that the resulting file looks like this:

"G. KRESSLAR", "9618 W. APPALOOSA DRIVE", "SUN CITY, AZ 85373"
"SHIRLEY ALLEN", "7272 W. VIA MONTOYA DRIVE", "GLENDALE, AZ 85310"
"LOUIS VALDEZ", "244441 N. 86TH AVENUE", "PEORIA, AZ 85383"
"DONNA NEWBON", "3231 W. DENTON #D, "PHOENIX, AZ 85017"
"SARAH WILSON", "6534 W. PALO VERDE", "GLENDALE, AZ 85302"
"W. GRISAMORE", "10017 W. PALMER", "SUN CITY, AZ 85351"

So far I'm stumped on that one. Any ideas?

Ok, I tried this and have what I need.

sed 's/^/"/' < in-file | sed 's/$/"/' | sed 'N;N;s/\n/, /g' > new-file