Bojan wrote:Thanks guys. Err . . . actually, I was looking for theory

Ah, a man after my own heart who wants to know 'why' as well as 'how' !
The first assumption has to be that we are talking about using the amp in 'clean' mode. We are not trying to overdrive the input.
This is because repeat echoes and reverb sound awful if distorted. This means these effects should be the last thing in the chain before the amp input,unless you use a foot volume pedal, in which case that goes before the amp input. I'm a big fan of the foot volume pedal - no fiddling with guitar controls and taking your eyes off the audience when playing live. Also, if you have a lot of effects and there is a bit of background noise, tip back the pedal and that all disappears at quiet moments. Lastly, tip back the pedal at the break and you don't have to run back from the bar when the guitar takes off into howlround half-way through the meat raffle.
The reason for putting the echo in front of the reverb is to imagine a big hall with hard walls. Hit a single note. The first thing it does is to bounce off the walls and back to you as discreet echos. Then those echoes bounce around, reducing in volume and merging into each other (reverb).
Before the echo come add-on effects such as tremolo, phasing, chorus. They are all adding a variation to the guitar signal, which can be clean or distorted.
Ahead of them comes the equaliser, to vary the sound (whether clean or distorted) before the add-on effects.
Right at the front comes a distortion unit (if you use one). Whether distortion or edge, it changes the fundamental sound of the guitar. It says what sort of a guitar sound you want to make (even if you are going to modify it with effects later in the chain) so it has to come first.
So that's my theory. Guitar - distortion - EQ - Effects - echo - reverb - amp.
Ray