In reply to Malpractise: Done numerous repairs to my POD Black Ice, inners for plastic boots and all sorts of other exped running repairs.
The quick option is basically to patch both sides using adhesive. If you have a Thermarest repair kit or and Ortlieb Drybag repair kit available they work but are very expensive and only handle small repairs, although they do them very neatly. If you don't have one of them and for bigger repairs you will need something to patch with and something to stick with.
For tears it is generally worth trying to sew them up a bit. A quick zigzag stitch along the tear will help hold it together as you cover it with the glue.
As far as the patches, pretty much any outdoor related material will do. Generally the heavier duty the better. Some tents come with repair patches, otherwise start looking at cheap things like stuffsacs or an old rucsac would also be an obvious choice. A non-PU coated cordura is good for the inside because the glue will be able to key to the weave of the fabric better.
As far as glue goes, the best stuff (and IMO really only stuff worth considering) is shoe repair glue. The branded stuff is 'Shoe Goo' but cheaper versions are available. Basically, the stuff will pretty much fix any hole/tear by itself and the patches either side are really just a way of keeping the layer of glue in place whilst it sets and providing some extra protection afterward.
Fill the hole and cover both sides liberally with glue, apply the patches to both sides, place a bit of protective plastic (offcut of a poly bag) on either side (in case glue oozes out), then place the repaired section between two flat surfaces, weight it down with a few kg and then leave it overnight.
For a rucsac base repair you may find that the outer patch eventually comes off. Don't worry, just put another thickish layer of glue over the hole and put on another patch. Even if the patches aren't great, the main thing is that you will be building up a thicker and thicker layer of glue over the hole and will probably get to the stage it is so thick that the patch ends up being redundant.
HTH