Several articles appeared recently, describing the surprising strategies that some plants have for eating meat. Not Pitcher Plant and Venus Flytrap - too obvious.

This from Science Daily:

Plants like petunias and potatoes have sticky hairs that trap insects, and some species of campion have the common name catchfly for the same reason.

Professor Mark Chase, Keeper of the Jodrell Laboratory at the Royal Botanic Gardens, Kew says, "Although a man-eating tree is fictional, many commonly grown plants may turn out to be cryptic carnivores, at least by absorbing through their roots the breakdown products of the animals that they ensnare. We may be surrounded by many more murderous plants than we think."

Also mentioned in the article, Darwin's interest and writings regarding plants that are generally accepted as carnivorous:

"Carnivorous plants fascinated Charles Darwin, and he and his friend Sir Joseph Hooker (Director of the Royal Botanic Gardens, Kew at that time) had an extensive correspondence concerning them. Darwin's book Insectivorous Plants played a critical role in the idea that plants could eat animals being generally accepted. Before this, many botanists (including Linnaeus) had refused to accept that this could be the case"

Tomatoes are also on the list of carnivorous plants, in this article. "their furry stems grasp the legs of small bugs and then, once they've died and fallen to the ground, the plant soaks up their nutrients through its roots. "

Here is a review of the original article, "Murderous Plants", and if you have access to scholarly journals, you can find more in the original paper. (2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161, 329–356). Better - here is a link.

I'm not sure how this information can be applied in the garden - probably, only in theory. No one has tested this aspect of gardening. I propose that this is another benefit of garden diversity. If your tomatoes and petunias capture insects, then maybe your peppers will be aphid-free?