This mod expands on farming a little by making pumpkins and flowers growable, and adding fruit trees and new crops. Here's a demo vid by Xenoph showing off some of the new content (note that video was made for v1.0).

And here's a more recent (v1.2) vid made by Fsmunro! Cheers again.

And more recent still (v1.3), compliments of MisterMinecraftable:

Common seeds are gained by tilling the ground around the plant you're after - till the grass near a pumpkin to get pumpkin seeds, for example. There is a small chance of getting random seeds from tilling the grass anywhere (better chance with a diamond hoe). Eating watermelons will also sometimes give you watermelon seeds. Common seeds include pumpkin, watermelon, red and yellow seeds.

Hybrid seeds are gained by harvesting wheat (random chance to sometimes drop amongst normal seeds), or by combining red dust with seeds, causing them to mutate. These hybrid seeds will grow hybrid wheat, which is like normal wheat, except it grows up to 3 blocks high (note that fertiliser will only fully grow one block of hybrid wheat at a time, you'll have to wait for it to grow higher on its own).

Hybrid seeds can be spliced with common seeds to make more advanced crops, including corn, cotton, tomatoes and lettuce. Corn will grow up to 3 blocks high, cotton is craftable into string, and tomatoes and lettuces are delicious! And corn kernels (not corn seeds) can be smelted into popcorn!

Tomato and cotton plants can bear multiple times, they aren't destroyed when harvested, and will regrow their product.