My own personal opinion is that you have to expect some upfront costs if you're serious about doing it right - either your own time and the worry that you somehow didn't do it right (and the worry that you're giving away your product) or the cost of buying the "expert's" product...
BTW, another easy one I've seen for web apps is just to allow the local address(127.0.0.1) to be used after 30 days.
>These are very effective. But there is some upfront cost.
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>Here's some ideas:
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>Idea#1: Only allow 5-10 records in your main databases. This will allow them to get a look and feel for the program.
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>Idea#2: Hardcode a date into your startup, and after so many days warn the user to register. When you hit the magic number of days, copy the databases out to encypted files so anything they entered can be recovered. Zap the databases you want, and they will be starting over. Be sure to display how they can contact you or order the software. This way I feel will either do one of two things depending upon the user's personality: buy or uninstall.