i understand it takes 1 or 4 days to get the VN visa depending on how much you pay. i don't want to hang around in BKK so can i have them mail my passport back to me via EMS?

or if not, have a courier service pick it up and mail it back? if so, any recommendations?

Is Visa On Arrival something that will work for you? If so, you can go online at some places like vietnamvisacorp.com and get the necessary papwerwork quite easily. Just fill out the online information and charge to your CC. They do have urgent (8hr) and super urgent (4hr) turn around times for a higher fee. Only need to provide your passport #. They will mail you back the visa on arrival paperwork, which you then can get a visa quite easily at the airport.

But, if you are coming in via land route, rather than major airport that can support VOA, or have another reason why you cant use VOA, then maybe not a choice for you.

i was under the impression is VOA is more expensive and a lot of wasted time at the airport in VN?

I think the embassy option is even more money than the VoA at the Viet airport. Or they're very close in costs. But yes, the airport VoA process is a big bore. (The Cambodians are faster by far if going there.)

Note, you can NOT do visa on arrival at a land or water crossing.