I'm afraid that I disagree. If you want really accurate alignment checks then yes the only way to do it is to go to an good alignment shop. However you can get fairly good measurements yourself. I does take a few hours to do, and is a real pain but it does work, and in some instances it has been known to outperform a bad alignment shop.
What you require :
# Flat floor to sit the car on (This is hard to acheive. I used laser level kits, and various shims to level out my garage floor)
# 2 18' lengths of fishing line.
# 4 axle stands
# verner calipers
Method:
1. Get the car on the level surface, pointing exactly straight ahead.
2. Optionally weight the car down with driver & passenger weights.
3. set the axle stands at each of the four corners of the car.
4. Set the fishing line length up running front to back down each side of the car at exactly the same height as the centre of the wheel, with the lines exactly parallel, and also equi-distant from the centre of the rear wheels, and also the front wheels (note that the front and rear wheels will have different distances from the fishing lines)
5. measure the toe by measuring from the fishing lines to the rear of the wheel rims and then to the front of the wheel rims. Because you cannot gaurentee that the steering is straight, the total toe is found by adding the left and right hand sides numbers for the rear of the rim and subtracting the total of the front of the rims.
For camber, I use a spirit level and length of wood to measure the angle of the rims, then use trig to figure out the angle. Do a search on this site to find the method for measuring the castor.
These method take a while to do, and require a real attention to precision to get close to a good figure, but they do work. They are certainly great for getting the car set to almost the right values for the first time after a rebuild and before driving to an alignment shop.
If you make an adjustment to any of the settings then you should really move the car forardwards and backwards a few yards, bump up and down on the suspension and redo all the measurements. real PITA. To help with this a set of slip plates under the front wheels with say some talc between them can allow the wheels to move as you adjust them.
Now, I'm about to get a huge amount of stick for having even suggested this.....
Si. :lala: | 
it just takes a bit of practice. i do not suggest even thinking about it though, even when i do eyeball it, it goes straight to my alignment guy (who for some reason i see quite regularly.) 
