regarding catching the ledgendary dogs:
mates, you guys are asking for trouble if you don't use a masterball on the dogs, and there hasn't been a proven effective way to catch it yet:
Mean Look, Arena Trap, and all those trapping moves are USELESS, as the dogs all know Roar... haven't you guys ever played the metal games??? Your best bet is the Shadow Tag ability (wobbuffet... or wynaut) which prevents the opponent from escaping battle, but i've never had the chance of trying that out myself... i only knew of the why family's exsistence after i've caught the dogs...
Other than that, mean look arena trap etc etc have all been proven to fail (and after they proved it failed, the dogs never showed their faces again, just too unlucky) Its hard catching the dog without the M.Ball, firstly because most prople try to find it using the repel method, but the dogs are much faster than most pokemon of the same level. I suggest you train up a parasect and max out its speed (100+ at least...) so make it lead the party and stuff the repel crap~ the only pokemon faster than the dogs at this point is a crobat and crobats don't know anything that can stop the dog from escaping...
Theres also a theory about using taunt, so the dogs would stop roaring ... but the thing is the dogs either roar or run... only way to stop them from doing both is to put them to sleep (or paralyse them... no longer useful in the nature versions because there isn't such thing as "fully paralysed" =\)
good luck catching the dogs with an ultra ball... i did but... i was very lucky i met them... once again don't waste your time using mean look (you'll be sorry...)
Frank