Why not try to grow yourself some free flowers (and food!)? A variety of plants and vegetables can regrown from the inedible parts we usually throw away. The methods for regrowing many of these plants are quite similar and some can begin to show results within days. Its best to try and grow these indoors at this time of year and transplant the cold-tolerant ones outdoors once the weather improves.
First, a word of caution: these will not regrow the edible orange taproot, just the main plant. The top of a carrot grows into a pretty houseplant with fern-like foliage and lacy white flowers. You will need to keep about 2cm of carrot around the top. There are a number of ways to regrow these. putting them on damp newspaper will cause them to start sprouting roots and can be planted into soil. These should start to grow in a matter of days.
The top of a pineapple, if planted, may regrow into a spike-leaved houseplant similar in appearance to an aloe vera. Cut away the leafy top about 2cm below the leaves, trim away some of the lower leaves and cut the flesh away carefully from the base of the leaves. Allow the head to dry out for a few days, then suspend it with toothpicks over a glass over water in a sunny area. This way you can see when roots begin to grow and transfer it to a pot. If you are very very lucky it may even produce a tiny pineapple from amidst the leaves.
Celery can also be regrown from the root. Cut away the base with about 2cm of stalk on top. Place it in a dish of shallow water in a sunny location. The central yellow leaves will begin to grow. These will regrow into whole plants that can be transplanted to containers and produce edible stalks. They prefer sunny areas and need lots of water for the stalks to grow well.
Similar to celery. Cut the base away with about two inches of stalk on top. You are looking for the leaves in the centre to be yellow. Float them in about 3cm of water, changing it every 2-3 days, and plant them when the roots appear.
The immense central stones can sprout into a sturdy plant. Remove the pit from the centre, been careful not to damage the brown seed cover. Wash it gently with warm water to remove any excess flesh. With the pointed side up press toothpicks into the pit to balance it over the rim of a water-filled glass. The rounded end of the pit should be half submerged in the water. Place it in a bright, temperate area and change the water every 2-3 days. After 3-4 weeks it will have established roots, lost the brown outer skin and begun to sprout. It can then be planted in an indoor pot.
Lettuce plants can often be regrown from the stem. Cut the leaves about 2cm from the bottom. Similar to celery and bok choi the base can be placed in a dish of water to grow. Change the water every 2 days and plant it once roots have appeared. They usually wont regrow quite as large as the first plant and the leaves become bitter if left for too long.
As with all vegetables be sure to check anything you intend to eat for pests or signs of rot. Given the time of year most of these will have to be grown indoors, and the more tropical ones will need to remain indoors all year round.