Hi
I was just wondering if it is advisable to buy a cover (or something) for your backpack for checking in at the airport because of the straps and different zips and compartments.
If anyone has bought such a thing, can you please let me know where to find one!!
Hope this makes sense!!!!!!
Thank you, Cez x 
1) Definitely cover up your pack if you want it to last, at the very least have something to fasten the straps to the pack, making it more compact.
2) Cheapest way to do it: Big plastic (trash) bags and (duct) tape. Outdoor stores sell some sturdier plastic bags and rain covers specifically for this purpose, but if you fly only twice on a trip, it is not worth the money.
Ocassionally it pays to buy a cheap, supersize duffel bag and stuff your backpack in. (Only works if your pack is not too big and the duffelbag folds easily into your backpack when empty.)
Some airports offer a wrapping service: they wrap your luggage in plastic for not too much (initially meant to prevent unwanted access to your luggage by freight handlers or so). But this is only available on big international airports. I would go for the d.i.y. with the thrashbags and ducttape if you only fly twice during the trip. If you fly more, I'd really recommend a 'flightbag', available at travel-/outdoorshops. You have them as a duffle and/or as a flightbag/raincover, which can be handy if you're going to asia in the rainy season for example...
Yes, I would find a way to cover up all the straps. I worked as a baggage handler at the airport for a while and I can tell that some bags do get damaged. The first thing is that they can get stuck in belts. This can either cause them to rip, or it could simply confuse the system that brings the bags to the right place and it may get lost or delayed.
Another big thing is the unloading. When the flight arrives, we would have to unload all the bags as fast as possible onto the belts. This means that we would just pull them out from the container, and we didn't have time to be too careful. If a strap was caught on the container or another bag, it could rip as we were trying to pull it out.
I dunno if you've already bought a backpack or not, but I bought one that allows me to zip away the harness... so no straps or anything stick out.
...and they have the wrapping service in most airports ion Australia now... not sure about other coutries though.
You can buy zipped bags which you can put your backpack inside, zip the thing up and put a padlock on it. Sort of turns your rucksack into a suitcase for you to check it in. At the other end you can take the rucksack out, and stuff the outer bag away somewhere.
Sorry if that's not very clear - don't know exactly what the things are called, but I have used them in the past and found them useful - both for planes and for putting luggage in the holds of coaches etc. They won't stop any determined thief who could easily cut through them, but they would stop someone idly going through your bag.
+ stops the problem of all the straps etc at checkin.
All this is good UNLESS you are going through/to America....see my post in General talk about my experiences there.