Is there a calling card which satisfies the following requirements:

1. Can be used globally
2. Re-chargeable
3. Has voice mail feature and the voice mails can also be retrieved globally

Thanks in advance.

Unisys provides the integration you are looking for:
  [pdf] http://www.unisys.es/comm/AssocDocs/PrepaidCard6.pdf

Ekit additionally allows _online_ access to messages:
  http://www.ekit.com/ekit/home/


If you decide to split these features up, or that you can do without
the voice mail, you can find a suggested brand name based on your most
common calling locations:
  http://www.phonecallmall.com/cards/

Some other features you may be interested in as well, not matching the
criteria above:
  http://www.worldxs.net/traveltel.html
  http://www.getonecall.com/features.html
  http://www.worldxs.net/world800.html


Thank you for choosing Google! Answers.

Offerings from ekit satisfy my requirement, thankyou.

http://www.callingcards.com

You might want to try the Sam's Club AT&T Pre-Paid Calling Card or
Price Club's Sprint Pre-Paid.  It's cheaper than what you'll find
internationally.