http://www.mongoosepublishing.com/phpBB2/viewtopic.php?t=24186&highlight=water+effect
The pictures are very big. The first picture shows the GW water effect (I put some on the base, and it just flowed like slightly thick water).
The subsequent pics show the woodlands scenics stuff.
GW is Games Workshop, a miniature wargames shop common in British cities. For Vallejo and Woodlands scenics water effects, you should probably check for ian allen bookshops in your town, and if there are none of them, try model train shops and model shops. Both are reasonably likely to stock water effects, but you can always ring and ask.
Have a look at this:
http://www.woodlandscenics.com/
Go to landscaping>> Water
Gives you some pictures of how it is applied.
For a uk stockist go here
http://www.thesignalbox.co.uk/index_new.php?pg=1
For a little tutorial on making a water scenery piece
http://www.terrainthralls.com/articles/watereffects/firstpage.aspx
Terrain thralls is a good read for scenic modellers anyway.
If you need any more pointers, just ask.