Using ladybugs for organic pest control?

[Rooney]

So I just had to pull up one of the raised beds of lettuce because of those nasty almost microscopic aphids.   I have been researching and think we may start releasing ladybugs out there.  Have any of you ever used these for pest control before?  I have always liked them anyway, so it wouldn't bother me having them out there.  Just wondering if any of you have ever done this?  Don't want to lose any more plants!

[Rooney]

This works!!  They are eating the aphids right up and the lettuce is looking healthier already.  We let go about 4500 of them and they went to work immediately.  I would imagine this would work in an outdoor garden as well.  They just have to have plenty of moisture and "food".  Here is a picture of them on some lettuce.