battikh wrote^^ he's talking about wpa, not wep. wep doesn't take more than 10-15 minutes (if you type really slow and take coffee breaks way too often)... and in worst cases, doesn't take more than 1-2 hours if you're not generating traffic yourself...
for wpa it will take much more time if you're bruteforcing, as kareem said. and using dictionaries to speed up the process is kind of useless in lebanon if people use arabic words. take for example the word "3arabeh". you can write it "3arabeh", "3arabe", "aarabeh", "aarabe", "arabeh", "arabe", "3arabi", "aarabi", ... so many combinations for just 1 word. so good luck in making a usable dictionary for arabic words.
and using a pre-made rainbow table is also not that effective as the wpa key in generated using the passphrase, the ssid name, and the ssid length, so 1 rainbow table that works for 1 ssid is completely useless for another ssid.
Thanks for clearing up the situation.