My el-cheapo manifold.

[drakeskakes]

Not sure if this has been built on here before, but I though I would toss it up.

I built a 4 way manifold. It cost about $25 using parts from Harbor Freight.
I liked this design because if I wanted to add another valve/barb for forced carbonation lines or I squeeze in a 3gallon, it can easily be done.

Putting it all together in the store...

 

[Conan]

Nicely done. Much cheaper than the machined aluminum ones and serves the same purpose. Kyle

 

[Toga]

Your set up is indeed cheaper than a manifold but you do not have check valves for each line to prevent keg talk and flavors mixing. This is important. You can use inline check valves to acheive this. I recommend the Kynar valves. You can find them in small quantities on fleabay for just a couple $ each or less. I think I paid $1.50 each when I bought them last spring.