How many ladybugs did you have? I got a package that contained about 1500 ladybugs and dumped them all over my balcony, making sure there were quite a few on the infested plants (I had em BAD!) Within a week, almost all of the aphids were gone. after 2 weeks all the ladybugs were gone. I just buy a new bag of them about every month-month and a half or so. One of these days I'm going to have them lay eggs and then I will be set.

I've heard that if you can find ladybug larvae, they do a much better job, and also tend to stay put better but I can't find them anywhere locally.

Also, there are other bugs that will eat aphids. Preying mantis and lacewings also do the job quite nicely I've been told.

I would love to use on of the heavy duty insecticides like seven, but since I have tomatos, I can't do that.

I've bought a pint of about 2,000 Ladybugs twice, followed the instructions (applyied them directly to the affected plant at dusk and misted the plants with water each day after), but they never eat enough of the aphids, don't stay on my balcony or just die. I'd like to try the preying mantis cocoons (especially since the mantis' eat caterpillers and almost all other problem bugs), but they really creep my wife out.
My little apple tree was so infested that, last night I just clipped off the new growth where they were literally covering and saved as much as I could by squishing them where they weren't so numerous. today I'm going to spray it with water and maybe get any straglers. If they start returning I'll try the oil based insecticide soap. I heard that the bananna peals on the soil make the sap that the aphids like so much taste sour and then they leave on their own accord, but it takes some time to start happening. They do have a three in one spray that is designed to be used on fruit and vegetables. It smells kinda funny (like old vegetable oil) and you have to use it every four days or so, but it is safe for veggies. I'll check the name at home if I get the chance and post it if you're interested.

Power to the Peacefull

the best thing for aphids is insecticidal soap but you might want to try brushing them off manually before especially on the most infested places-i usually do this before even applying any insecticide that way you have most of them gone already. I would suggest you keep on using the insecticidal soap just remeber you have to really cover all the green parts of the plant and do it every three days at the beginning. With the oil-based insecticide you also have to be careful not to over-do-it because you can get leaf burn from the oil getting clogged in the stomatas (which is how the plant breathes). A fine mist is all that is needed. also be careful about not using it on a sunny day as that can burn the leaves also. maybe theinsecticidal soap was drying out too fast-maybe try applying it in the cooler evenings...
good luck!

Thanks guys.