1st time compressed air use, hints & questions.

[snowdog]

After beign tired of manually cleaning my keyboard and coolers all the time i bougth my 1st can of compressed air, I know I shouldn't use this when the device is powered, and that it can cause condensation, but are there any other things I should look out for?

Also how long can I expect this can to last ( how many ''average'' dust removal jobs), its a 400 ml can?
Anything else that is important?

 

[snowdog]

Just finished doing my g11 keyboard outside, will do my coolers later today, the can already feels lighter, you get quite little air imo for 10€'s, yeah the can got pretty cold, but still ok to the touch.
Should I watch out for something when doing my gfx-es zalman or my cpu's freezer?