I hope this isn't a known bug/exploit, but I checked the 1.01 known bugs topic, and couldn't find it. Anyway, there is an exploit with the Ferret Familiar (Lawful Netural):
Prior to entering the Duchal Palace for the "transfer" to Athkatla the familiar can be instructed to pickpocket the PC for, say, the Boots of Speed (haven't tried with other items but I suspect it would work on almost anything that isn't a container). When the familiar is found in Irenicus' Dungeon the PC can then ask for all of the familiar's pickpocketed items and ... instant Boost of Speed.
The familiar should probably also be robbed of all its items when transferring between BG and BG2.
