I had money to burn so I bought the Dagger of Venom and gave it to Jahiera to use in melee situations (hey, it's better than a club!). I use a short sword +2 for Imoen, so she can actually make contact when backstabbing. Actually, Jahiera hasn't had a chance to use that dagger yet, but I bet it will be fairly effective in the hands of a fighter. I haven't faced any really tough mages yet (I'm only in Ch. 5) so I haven't needed to use a poison dagger yet. Butt loads of arrows/bullets seem to work just fine so far