I also note they say it's not a multiple entry visa, so if you come to Thailand, and then go to Cambodia, the Thai visa is 'finished' and you'll have to get another visa, or use a 15/30 day visa-free entry to come back.

Also, you can't pay both fees at the time of getting the visa. If you get the visa from the Thai embassy or consulate, you pay them the Thai fee, and then when you get to Cambodia you still have to stand in line to pay the visa fee on arrival.

In all, it doesn't sound like a good deal the way it's being presented at the moment.

This looks like a Graft corruption/scamming charter to print money to me. The joint Cambodian border official & Thai visa pimp scamming was rampant an blatent last week on both entry to and exit to Cambodia:
1) Folk being charged 1000 bhts for cambidian visa ($30 - official cost is $20)
2) People being charged 100 bhts each for an entry stamp - 0fficially no charge
3) Private cars & taxis being staooped at a road block 5 k's from the border and being charged 50 bhts per car - outright Officialdom corruption..

lets see how it goes..?

The common visa is something that has to be obtained in advance. In theory, it might remove some of the hassle at land crossing, but probably not. The Poipet crossing has always been a problem, and probably will be for a long time to come. It's the classic example of people trying to save up buck by traveling by land ending up spending a lot more time and money.

I am totally confused by all the visa stuff. My original itinerary was to fly from home into Phnom Penh for 4 nts., Battambang 2 nts., Siem Reap 10 nts.-then cross overland into Thailand. Itinerary for Thailand not finalized yet but want to spend 4-5 nts. Bangkok with day trip to Ayuttathaya, 2 nts. Kanchanaburi, 4-5 nts. Chiang Mai with trip to Chiang Rai (Golden Triangle), ending our trip with 10 nts. beach-don't know where yet. Husband is experienced scuba diver so he wants good diving. Time of year for trip most likely will be December 2013-Jan/Feb 2014. Can be flexible with time as we are retired.

I have learned that if you enter Thailand overland you get a 15 day tourist waiver visa. In order to get 30 days you have to enter by air. No charges. Our total time in Thailand amounts to about 22 nts. which is over the 15 allowed. A person on TA told me I could enter Thailand first from home which gets me the 30 day-do all I have planned except for the beach, go to Cambodia, re-enter Thailand overland which gets me 15 days and then could spend the 10 at the beach and not get into any trouble?? Is this possible? I thought I'd have to apply for some kind of other visa which has a charge to it. I've gone onto the website for US citizens going to Thailand but I must admit I just don't understand as my trip doesn't seem to fit any criteria listed. I don't understand why it's 15 days by land but 30 days by air??

Can anyone help me figure out what to do??

Get a 60 day visa for Thailand and use this when you enter from Cambodia. Fly into Phnom Penh as planed getting your Cambodia visa on arrival for $20 US (no scams here). When ready take a bus or a taxi to Siem Reap. Then take a taxi to the Poipet boarder crossing and use your visa to enter Thailanda. Get a tuk tuk to the bus station and a 1st class bus to Bangkok. As an alternative to the bus there should be taxis on the thai side that will take to Bangkok

Either the 60 visa in advance for Thailand (get it in advance from the Thai Embassy in your country) as per Scotters above works, or you can go to Thailand first, flying in you get 30 days, then to to Cambodia, come back overland and get another 15 days as you mentioned works.

Thanks Scotters and Kathie. My husband is leaning towards just applying for and paying for the regular tourist visa for the 60 days. If I can find a decent priced open jaw air ticket we will most likely do this. But it's nice to know that the advice I got from TA forum on 30/15 doing 2 different entries into Thailand was accurate-thanks Kathie for relieving my anxiety about that.

Our trip isn't until December 2013-January 2014 so I can't book the international air yet.