While they are hard to come by, you can still get one if you know where to look. There are services such as www.mytollfreenumber.com which own blocks of memorable 800 numbers (as well as 888, 877 and 866). Depending on your needs, you can find a premium 800 number to use for specific geographic areas only (businesses across the country can share the same toll-free number, while having exclusive rights to the toll-free number for calls originating in selected zones) or for the entire United States.
These toll-free companies make their money from the set-up fee, a monthly fee based on the value of the number and on the number of zones selected, and by providing long distance service. While the long distance rates may be slightly more, if you believe your response rate would be higher with a memorable 800 number, then it might be worth the investment. In some cases you can negotiate to buy the number and switch it to your long distance carrier.
So don't give up hope. If you really want a memorable 800 number, you probably can get one. You just have to know who to call.