Next to selected packages of different veggie seeds to create little vegetable gardens, another variation is a mix of seeds to grow herbs for tea. This is one of my favorite, since these include more unique plants which aren't often found in gardens and shops. Chamomile, mint, st. John's wort and marigold seeds would make a fun and healthy assembly!
Here are two other original seeded gifts I stumbled upon: tiny postcard gardens in the shape of a garden or botanical garden.
The second one is also a great invention: recycled paper filled with seeds. After use, you can put it in the earth, and with some water and patience the seeds will grow into anything that flowers! You can buy it on the internet, or make plantable paper yourself!