Email inviting you to download the newest PDF reader
Email inviting you to download Google Earth
Basically they just want you to pay for a product you can download for free. This time it's Adobe PDF Reader and Google Earth that are being targeted.
Be alerted when you receive an email with subjects like:
New 2010 Version for Google Earth
Update to PDF Reader 2010 for Windows
Get more out of Google Earth
New PDF Reader with Activation Code
Update your PDF Reader for Windows
Do not click on any of the links, and don't be fooled if the URL doesn't look 'funny'.
They might use URL shortener services such as bit.ly or tinyurl.com to hide the real URL.
If you are really interested in any of the forementioned applications, go to the original site and download it *for free ;)* from their website.
Screenshot of the 'PDF' website
Screenshot of the 'Google Earth' website
Conclusion
The conclusion is pretty simple: delete these emails and never reply on them !
If you are unsure if the email is legit or not, I would delete it anyway.
For instance: Google will not email you with a request to download their Google Earth application and pay for it.
You can always use URLvoid and VirusTotal URL scanners as a reference.
Be safe people, and don't fall for these tricks.