Travel Technology - any recommendations for cell phone rentals

I will be spending about 3 weeks in seoul and for whatever reason my company doesnt want to pay for a cell phone rental... does anyone have any recommendations on a good/cheap cell phone rental mostly just to keep in touch with the locals im working with or in case of emergencies?

Don't bother with a rental. Buy a cheap unlocked GSM phone and get a local SIM card. You'll pay WAY less money that way, plus you'll have the phone for future trips.

Japan and Korea do not use GSM ,
but they do use 3G 2100
http://www.worldtimezone.com/gsm.html

Rally

A rental will likely cost you more. Not a good idea in this day and age. As suggested, get a gsm phone that has the 2100 3G band and get a prepaid sim from one of the carriers that uses the 2100 3g band there.

are there any real cheap 3G phones ?
good for USA 3G and the rest of the worlds 3G too ?

I might want to get one to tether to my laptrop

Rally

There are actually NOT too many phones that support the North America (AT&T) 3G bands and the rest of the world 3G band. So, if you are with AT&T, some not to expensive ones are Blackjack II and treo 750. If not, there is no need to buy a phone with 850/1900/2100 3G bands. Just get one with 2100 3G.

are there any real cheap 3G phones ?
good for USA 3G and the rest of the worlds 3G too ?

I might want to get one to tether to my laptrop

Rally

Look for a Nokia E65 on Ebay. It is a rock solid phone, will work in Korea, and will work at EDGE speeds in the US. Deals can be had because the phone has been superseded, but it still looks good.

See, e.g.:

http://search.ebay.com/search/search.dll?sofocus=bs&sbrftog=1&from=R40&dfsp=32&satitle=nokia+e65+unlocked&sacat=-1%26catref%3DC6&sargn=-1%26saslc%3D2&sadis=200&fpos=48075&sabfmts=1&saobfmts=insif&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=32%26fsoo%3D2&fgtp=

get a prepaid sim from one of the carriers that uses the 2100 3g band there.

Can someone confirm the availability of prepaid SIM's in Korea? I am unaware of such offerings there (as in Japan, for that matter).

Any 2100 3G phone will work, but this may entail using a foreign SIM in roaming mode, which depending on the types of calls made may become more expensive than a rental.

I think that Korea is like Japan. Non-residents can't buy a prepaid SIM, but you can rent the SIM cheaply at the airport. United Mobile's roaming SIM works pretty inexpensively in Korea:

http://www.united-mobile.com/?p=rates&from=103&to=480

United Mobile SIMs have a UK number.

Don't bother with a rental. Buy a cheap unlocked GSM phone and get a local SIM card. You'll pay WAY less money that way, plus you'll have the phone for future trips.

This is the way to do it. Just make sure that you get a decent plan/rate when you do buy. There are usually several choices and if you are planning on using it sparingly, you should get the appropriate plan.

This is the way to do it.

Let's get this straight and not confuse the OP: this is generally good advice, EXCEPT for Korea (and Japan) where GSM is not used at all, and prepaid SIM's may not be available for non-residents due to government regulations.