I heard this idea presented tonight before Ma'ariv.
The speaker (one of the members of the local kollel) mentioned that his brother-in-law had an idea for a business. Since everyone knows that the air of Israel makes a person wise (Bava Basra 158B), he wanted to sell bottles of Israeli air to tourists. Whenever they needed a burst of smartness, such as the night before a test, they'd open the bottle and breathe in the inspirational air.
Of course, this wouldn't really work as a practical financial venture, but it does work with regard to doing teshuva.
The Ba'alei Mussar write that an effective way to do teshuva is to make one small, consistent change to one's life. The speaker quoted his rebbe in Israel as commenting that the best time to take this small change upon oneself is to do it during Ne'ilah, when you really feel the power and awe of HaShem's kingship and the overall spiritual rush of the conclusion of Yom Kippur. By doing this, you are effectively capturing that moment of spiritual elevation and inspiration in your own small bottle.
Every time you perform this small change - every day - it's as though you will be sampling some of the power you captured from that moment of acceptance during Ne'ilah. Each day, you will, to a small degree, re-experience that feeling of spiritual fortitude and inspiration. By doing this small thing every day, you create a link that strings together all the days of the coming year that leads back to that awe-inspiring moment of Ne'ilah.
And that is how you can create an effective change that will have a lasting impact - from this Ne'ilah to the next.