Eco notes that grow: Yep thats right these inexpensive cards (if you stick them in a pot with soil) will grow as the paper is embedded with wildflower seeds. You could buy a small clay pot (perhaps paint it a color) with some soil raped up with the Eco note. The recipient can plant the card and watch it grow. I would suggest that you do not plant the card straight into the ground as the worms in your garden may eat the contents (that's right - it's compostable).
Manure tea: That's right you read me right. This is the perfect product to help your plants grow and flourish. They say that compost tea is good for the garden. True but so is manure tea. This product conditions the soil and provides nutrients to aid in the growth of your garden. You could even purchase this in a gift pack.
Solar lanterns: These are a great way to add light into your garden especially if you are renting and cannot modify the landscape. I live on the second floor of a condo complex and have no land to garden in and therefore cannot have a lighting system so this helps me by adding light. They come in a variety of styles and colors to choose from.
Something handmade: Whether it's a planted pumpkin or a succulent pillow, something handmade shows that you took time for that person by making them something that is cute and from the heart. You can get creative and make something truly unique.
These gifts are reasonably priced, unique and perfect to add a pop of joy to your world or your friends. This would even be a nice white elephant gift.