I'm of the opinion people naturally resist change, especially when it comes to "technical" things. From this resistance spawns a huge myriad of logical and illogical reactions to change with which they are forced to cope. But take courage ye ole implementors of technology change, there are ways to ease the pain.
#1 - Let it flow from the force. In this case the "force" is not a mystical power but your employees or customers, the ones who will really be using this stuff day in and day out. Involve them early and often in the development process. You may think you know a lot. But, I guarantee your end users will give you great ideas and perspectives that would have taken you much longer to stumble across. If change is generated from their ideas then acceptance will be more likely.
#2 - Beware of the feature creep. "Feature creep" is a term used to describe how a simple project turns into a huge project as those involved start requesting little additions here and there. Don't get me wrong, I'm a fan of not limiting ideas, thinking blue sky, etc. As you involve your end users, just know that you shouldn't add everything that's suggested. If you do, the end product may turn out to complicated to use or take so long that everyone loses interest. Not good for helping your acceptance.
#3 - Train, train, train. Remember that most your end users were not specifically involved in development. So it is a mistake to assume they're playing on the same knowledge level you are. When implementing a new website, ecommerce store or workflow automation be sure to budget plenty of time for bringing others up to speed. Change is resisted most often due to lack of understanding.
#4 - Track results. Whether it is sharing cost savings, increase revenue numbers or tying incentives to the new technology, encourage your employee or customers about it by letting them know about the success and how they have contributed to that. Everyone likes a pat on the back and to feel as if they're making a difference.
New ideas, processes, techniques, software, etc. happen everyday. Always continue looking for ways to improve and grow. Just remember that when technologies do change it effects people and they are your most valuable asset. So implement the change if it is the right thing for your business but also implement the support that will allow your end users to skyrocket the change's ROI for you.