Canon-nonfash-flash-seconds
A95 - 1.6 - 3.4 seconds
SD600- 1.3 - 1.8 to 3 seconds
A540 - 1.5 - 4 to 6 seconds
A620 - 1.4 - 2 to 3 seconds

To find this type of informations, go to:
http://www.steves-digicams.com/hardware_reviews.html

Select the review for the camera you want.
Then go to the page called "Steve's Conclusions"
Look for the paragraph on "Performance"

Note:
Shot to shot time with the flash active is influenced by how fresh your batteries are and how far you are from your subject.

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