No, the answer is that the wiki has no data for IAH, which is exactly what the OP wrote.

Any info on wait time for walk-in's at Tampa airport (TPA)?

Please update wiki for me, since I can't...
ORD - Yes [300m] (11/14/16 1:30pm)

Got conditional approval on 11/12 and checked online for interview time, and the earliest I can get is Jan 19, 2017. Travel in 2 weeks so decided to try my luck. Walked in at around 1:30pm, was told it's ok to wait, but they have to interview all those with appointments first. And they will ask all to leave by 7:00pm if no available spot showed up, even if waited for a whole day. If agreed then they put your name down.

Waited all afternoon, people kept coming in with appointments. At 3pm officers changed shifts. Around 6pm finally the room thinned out, and I was called in. The whole interview took like 5 minutes total.

Notes:
1. an officer said if really need to pick a day, come in Tuesday for your walk-in.
2. will call in all with appointments, does not matter they show up way late or hours early.
3. seems like they call in family members together even with different appointment time
3. bring a book or any elec. device with enough juice.
4. if you asked me - just show up around 6pm for walk in. chances are minimal to be called before that. but hey, who knows.

Done

I am getting my three kids global entry . Two of them have times one after the other on the same day and the third came back a week later and now no times left that day. Any chance they will interview my daughter at the same time without an appt. We leave for an out of country trip on Jan 7th. We are currently booked at EWR airport at the end of December. Its a two hour drive to EWR so it would be great to get them all done in one day.

I moved your question to this thread.

Maybe. Take a look at the wikipost. It's probably worth a try.

TWA884
Travel Safety/Security co-moderator

Tried a walk in at Newark airport on 29th Nov. Was told they don't do them

Just got approved for GE and the first appt is in FEB! Ridic.
Going to try your 6pm theory! Thanks!

Just added text anchors/a table of contents. Hope it helps! :)

^

JFK walk in 12/16/2016
 

JFK
Yes [40m] (12/16/2016 7am)

Curious as well for wait time at Tampa. Calling of course they say they don't take them at all, but have read people have done walk-ins here as well

Moderator's Note:
 

A recent post asking whether a passport is required to be brought to the Global Entry interview and answers to that question were moved to the following thread:
TWA884
Travel Safety/Security co-moderator

i also tried the same thing today first thing in the morning. No luck. I wouldn't bother at Newark without an interview.

I then spent the day on the GOES site chasing cancellations at JFK, EWR and customs house as i'm in town for the week (based in SFO with an appointment set in April and already been waiting for more than a month). A Newark appointment on Thursday opened up but i had meetings at that time and couldn't make it, then i hit gold...7a appointment at JFK opened up tomorrow morning. Booya!