If I travel overseas, how do I email various people back in the U. S.?

Depending upon your destination, your hotel may provide web access. 
Or, you may be near what are often referred to as a Cyber Cafe, where
you can pay an hourly charge to use a computer.

With that in mind, my recommendation is to set up an email account
with one of the following:
http://www.excite.com/
http://www.yahoo.com/
http://www.hotmail.com/

They will allow you to create a free account that you can access from
a web browser during your travels.  You can then send email.  In
addition, these services allow you to check your regular POP email
account that you may have now, enabling you to check your incoming
messages through their web email account (some charge a fee for POP
access, others are free).

Another option may require not extra setup on your part at all. 
Depending upon who your ISP is, you may already be able to access your
email through a web browser.  For example, AOL, EarthLink, CompuServe,
and MSN all allow you to do this if you wish.

If you would like to tell me who your ISP is, I can visit their web
site and see if they have that "web mail" feature.  Otherwise, I would
suggest a free account from Excite, Yahoo, or Hotmail.

I used this strategy during a trip to Italy and it worked like a
dream.

Also, below is a link to a list of International Cyber Cafe's, where
you may find places available at your destination.
http://www.cyberiacafe.net/cyberia/guide/ccafe.htm

Free email account hosts (ad supported):
http://www.excite.com/
http://www.yahoo.com/
http://www.hotmail.com/

Please do not hesitate to ask me to clarify this answer if you require
additional help.

Another webmail provider is www.operamail.com 
Many public libraries offer internet access either very cheaply, or
free. I've also seen terminals in tourist information centres, and
there are coin-op terminals in some railway stations and shopping
centres. This is from a UK perspective.

Remember to add your correspondents' email addresses to the online
address book before you leave.

Owain

In addition to several ISP's having the possibility of checking (and
using) your own POP3 e-mail account from any internet connection,
there are several other internet based companies/programs that give
you access to your own account, provided you know your login name and
your password(+ sometimes the name of your ISP),two of the better ones
are:
www.mail2web.com and www.twigger.com (especially European ISP's)