I just reread Michael Weber's book, Lifesavers. I'm sure others will agree-- it's such an awesome read. New things in the book catch my interest everytime I pick it up. So you know-- it's a book devoted to "improvisational magic." Not necessarily impromptu, but everything looks and feels very organic in performance.
For instance, I'm personally playing with the effect, Four Dollars in Change. In effect, a borrowed five-dollar bill is signed and (instantly) folded into an origami finger ring which the owner wears on her finger. A one-dollar bill is then borrowed, and it visually changes into the SIGNED five dollar bill. When the spectator looks down at her ring, it's openly changed into a folded one-dollar bill ring while she was wearing it.
Another noteworthy effect in the book is Dispensed Deception, where a borrowed ring changes into 50-cents. The two quarters are then put into a nearby toy dispenser machine. A plastic bubble pops out of the machine, and sealed inside is the spectator's own ring. I've actually done this on the streets when I was younger, and it always hit really hard. Again, it looks and feels very organic to the setting, as if magic is just naturally happening around you beyond your control. Everything is motivated and nicely orchestrated.
Overall, the book really has no filler in my opinion. It's filled with the kind of magic you're looking for. It's perfect for casual settings when you just want to show off at a bar or restaurant with some friends. There's some killer material I think you'll enjoy in the book reminiscent of contemporary televised street magic specials.
FYI,
RS.