Traditional thieves' tools might be suspicious, but no guard looks twice at a common deck of cards.

Benefit(s): So long has the rogue has access to a deck of cards, she can destroy one card to attempt a single Disable Device check as if she had a set of thieves tools. If she uses a harrow card for this purpose, she can treat the card as a set of masterwork thieves' tools (granting her a +2 circumstance bonus on the Disable Device check), though the card is still destroyed after use.