Packaged fruits and vegetables aren't actually convenient, as it's no more difficult to plop some pears into a bag yourself than to buy them already plastic-wrapped. Plus, you can reuse little produce bags. Plus plus, buying loose produce allows you to choose the best-quality items. Plus plus plus, it will save you money in almost every case. There seems to be an impression that pre-packaged produce is cleaner or more reliable, but this isn't actually the case. Adding unnecessary packaging to a product is simply another way to add the appearance of value and thus separate consumers from even more of their money, while contributing to packaging waste.
Effort involved: just bringing small bags along when you buy produce. (Did you see all the +es above?)
Image from: http://deadmonkeycomics.com/blog/2007/03/important-cereals-of-the-80s/
This is another of those strange Internet-magic sites where simply clicking causes website sponsors to donate money to a certain cause. The cause in question is therapy for autistic children, but this site also engineers donations toward literacy, rainforest conservation, child health, veteran support, animal care, mammograms, and anti-hunger initiatives. And seriously, all you have to do is click. Repetitive strain injury, here you come!
Effort involved: well, you don't even need both hands.
Image from: http://www.fotothing.com/MrSelfDestruct/photo/64b312c085584f3db53cd02d55ee5da6/
Charity credit cards only make sense for you and for the charity if you're a credit card user who might forget or neglect to donate to charity when not using your card. A summary of some of the issues can be found here. But if these cards make financial sense in your case, it's a useful way of supporting a charitable cause without even having to think about it - although not "even having to think about it" might be a slightly dangerous thing when it comes to credit cards...
Effort involved: Step 1) do a search for "charity credit cards" or "affinity cards" in your country. Step 2) sign up. Step 3) spend. Step 4) there is no step 4! You're done!
Image from: http://hellokittycreditcard.net/black-credit-card
Care packages are fun to put together. And apart from the postage, they don't need to involve any expense; you can simply throw things lying around your home into a box, and still be assured of a smile on the receiving end. Care packages tend to be the most effective when they involve items that the recipient loves but can't easily find wherever he/she is, such as, er, tortillas in a small Cambodian town...
Effort involved: honestly, standing in line at the post office might be the most annoying part of this procedure.