Question
Aphids are on my tomatoes.  Is there there any good way to get rid of them?

Answer
Depending on the number of aphids present and the size of your tomatoes, you have a few options.

If there are not very many aphids or your plants are small, you may be able to squish many of them by hand.  It may also be possible to dislodge many of them by spraying with a strong stream of water.  Be sure to spray the undersides of the leaves since the aphids are often hidden here.

Chemical control may be your only real option if the number is high or if your plants are large.  You can use organic products such as insecticidal soap, neem extracts or pyrethrins which are available at garden centers or synthetic products including those that contain dimethoate and endosulfan.  Follow the label directions closely since it is possible to injure the plants with these products if not properly applied.  Remember to coat lower and upper leaf surfaces.  You may need to reapply these products.