I'm selling software online and would love to know what everyone else is using for licensing and protection. I know Armadillo is popular, as is EXECrypter, but what else is out there?
This has been asked already in many places:
1) http://stackoverflow.com/questions/109997/how-do-you-protect-your-software-from-illegal-distribution
2) http://stackoverflow.com/questions/104291/trialwarelicensing-strategies
One option is Aladdin's HASP. It offers both hardware-based (USB dongle) and software-only based solutions.
Safe-net offers one.
Desaware offers one.
Disclaimer & plug: the company I co-founded produces the OffByZero Cobalt licensing solution, which offers turnkey software protection.
Bear in mind that protecting your application isn't just a matter of plugging in a third-party module. You also need to structure your code so there's no single point of attack (e.g. no single global variable like fLicensed) and, if on .NET or Java, employ good obfuscation as well.
Take a look at CryptoLicensing. You dont mention which tech you are using for your product but CryptoLicensing comes in three editions - .Net, MFC and ActiveX, so one or the other should apply to you.
You don't say for what type of application, but if you are using .Net there is a company that has two products around license management.
I have used their Intellilock product for managed applications and it works great.
You should take a look at LM-X License Manager from X-Formation for flexible licensing and protection.