Here is a cheat table for Bejeweled Blitz v1.0.6.4034 and v1.0.6.7260

You can use the cheats if You download cheat engine and the cheat table from here:
http://forum.cheatengine.org/viewtopic.php?t=529958

The options in the table are:

Add silver coins with key 1  (for v1.0.6.4034 only)
Enable gem swapping   (for both version)
Unlimited Time   (for both version)