So this is a hanging plant sort of thing? Tomatoes want deep roots so container gardening for tomatoes needs at least a 5 gallon bucket, which will be pretty heavy to support.

I planted my tomatoes in my upside down container a couple weeks ago.....and man oh man they are florishing! I already have a couple little tomatoes on the vine, and the vine is growing up toward the sky.....it is really amazing.......fun to watch and fun to grow

I tried this a couple weeks ago as an experiment and my two "guinea pigs" -- grape tomato plants -- seem to be fourishing quite nicely.

Here's the cheapo DIY version I made with stuff around the house:

Materials:
small tomato plant (it needs to fit through the hole of the bottle)
a large plastic juice bottle, gallon milk jug, or 2 litre soda bottle.
strong string or wire (nylon string is good).
a hook
a paper towel
black plastic
duct tape
larg-ish clear plastic bag
potting soil

Tools:
x-acto knife
scissors
drill (if you are using a hook)
long stick (about 1 foot)

1. Install a hook where you want to plant to hang from. should be a sunny place at leat 4ft off the ground.
2. Cut the bottom off the bottle with knife or scissors and poke 4 holes (for hanging string) about 3/4" from the edge of the bottom.
3. Cut 2 lengths of string, about 2ft long, and securely tie each end of string through the holes.

4. This is the tricky part: getting the plant through the hole.
Take your tomato plan out of its container, or cut the container off around it if it seems stuck.
Gently arrange all the leaves so they all pointing upward and gather them together.
Wrap the plastic bag around the plant so that a corner of the bag forms a point at the top.
feed the point of the bag through the mouth of the bottle, then tug on the bag while lightly pushing the root end. Keep pulling on the bag once the leaves are through to remove it.
Try not to disturb the roots too much as you are doing this

5. stuff a damp paper towel around the opening to prevent too much soil and water loss.
6. fill the bottle with potting soil, taking care to pack around the root without leaving air pockets. Using a stick will help.
7. hang.
8. Wrap clear and translucent bottles with black plastic or some other light-blocking material to prevent algae growth.

If anyone is interested, I can make illustrated diagrams.