With the right environment, many plants are very easy to reproduce from cuttings. One little known is the tomato. For folks in our area, Zone 9, there is little need to buy fall tomatoes or grow them from seed. Just pick your best producing tomatoes from spring, take some cuttings in late June or early July, put them in the right environment to root, and whalla, you have your tomatoes for fall. While going through some antique (junk) shops on vacation recently, I ran across this perfect little propagator (terrarium). Should be great for propagating cuttings, holding most of the moisture with just a tiny bit of air circulation. Not too bad for $20 with stand.
Another source for fall tomatoes, especially if you like to take a gamble on type, is to throw all of your bad tomatoes, bug damages, etc. in the compost bin. Till it up good about mid June and then wait for the seedlings to pop up in the compost. Now, this way you never know what you'll get, but that is a big part of the fun.