You can't go wrong with a handwritten thank you note, but why not say "thanks!" in a way that's creative and memorable? When someone goes above and beyond, find a meaningful, personal way to thank her: do something special for her, acknowledge her publicly or treat her to a gift of her own. And it doesn't have to cost money -- you can always give your friend an IOU for a car wash, homemade dinner or free babysitting.
Traditional Thank Yous
As Emily Post and your mother have always reminded you, if someone takes the time to pick out a gift for you, you can take the time to write a thank you note. The same applies when you've been invited over for dinner, received help on a project or supplied with homemade chicken soup when you were sick. Instead of buying a standard card at the store, make your own homemade card with colorful markers, saying "thank you" in different languages. If you're handy with a computer-based creative program, make a card incorporating a picture of you with the recipient or of the empty bowl of soup with "yum!" printed inside.
This One's for You
Show your gratitude by finding the perfect token or gift that will be meaningful to the recipient. Buy a gas station gift card for the friend who drives your son to batting practice each week. Give a gift card to a local plant nursery to the neighbor who cared for your plants while you were on vacation, or a jar of homemade salsa to the one who gave you fresh tomatoes from her garden.
The Gift of Time
For people always in a rush from one activity to another, the gift of time is often more appreciated than anything else. Offer to babysit for the busy single mom who brought you food when you were sick. Spend extra one-on-one time with your child at her favorite restaurant to thank her for helping out with the new baby. Volunteer at the church nursery to give full-time nursery personnel who watch your kids time to enjoy the service with their own families. If you've got a prized, close-to-work parking space at work, give it to a helpful colleague for a week to make her mornings less hectic.
Spread the News
Your friends and colleagues likely didn't do something nice for you because they were looking for public praise. Your thanks is typically sufficient, but sharing word of their kindness may also be meaningful to them. Take time at a Scout or PTO meeting to publicly thank a parent volunteer who works tirelessly behind the scenes. Write a quick note to the store or restaurant manager expressing your gratitude for the service of a particularly good employee. Send an email to your colleague's supervisor noting the value of his contributions to a recent major project at the office.