Here's a little technique I sometimes use for peeking; using the hologram on the front of a credit card as a mirror...
I'm sure you can think of many applications; there are any number of effects where you might have a credit card on the table... Try holding a playing card a few inches in front of the CC and tilted just so will allow you to peek the index easily, but the angles mean that the peek is anything but obvious from the spectators point of view.
I created an effect called "Credit Card Fraud" in which I use this technique to do the following... (I'm sure you can work out a method yourself ;o)
The performer gets a volunteer who is carrying credit cards, he explains that credit card fraud is a growing industry these days, and he's going to do an 'experiment' to see what he can do with one of the volunteer's cards.
The performer has been careful to ensure that only the front faces of the credit cards have been on display, he fans them and has one of the cards selected by the volunteer, the rest are placed on the table in front of the performer while the target card is placed in the centre between the performer and the volunteer.
Now, the performer addresses the volunteer by name, "Mr Smith", (this may get a laugh when the performer responds to his surprise that the name is written on the face of the card!), "You see that from here I can easily read the details on the front of your card... I can see the long number, the expiry date, and your name - it wouldn't be too difficult for me to memorise those details and use them at some future time"
"However, these days the security measures with these things is far more strict. There happens to be additional information coded into this card on the magnetic strip (or on the smart chip), but I'm going to show you how easy it can be to 'scan' this information"
At this point the performer carefully picks up the card with his right forefinger and thumb, making sure that only the face remains visible, and proceeds to 'scan' the card, either by 'swiping' down the magnetic strip with the forefinger and thumb of his left hand, or, if the card has a smart chip, by simply touching his left forefinger to the chip.
"OK, I've now scanned the information from your card and I'm ready to use it to book a nice holiday in the sun through my favourite online travel agents!
You don't believe me? Well, let me show you something" (Taking a credit
card of his own from his breast pocket) "If I show you the back of my card
here, you'll see some numbers running along the top of the signature strip.
The last 3 digits are called the CV2 number, or the 'signature digits', and
most reputable online retailers these days require this number before making
a transaction. So the info on the front isn't enough, but I've just scanned your card look". The performer holds up his left index finger showing the volunteer that there is a 3 digit number clearly etched onto the tip of the finger where he 'scanned' the card, amazingly, the number matches the CV2 number of the volunteers card!
As if that isn't amazing enough, under some circumstances and with a bit of
practice the performer can also end with this killer finish....
At this point, the performer has been careful not to have displayed the back of ANY of the volunteers cards, he notes this, putting the cards aside, and explains that if he were to defraud the guy in the 'old fashioned' way, he'd simply steal the card and use it on the High Street. However, in order to do that, he'd be required to give another piece of information to the shop, i.e. he'd have to sign the guys signature.
"Now many people believe that handwriting and signatures can reveal a lot about a person, but did you know that this can work in reverse? The invisible body-language 'signals' given off by a person can actually reveal a lot about their handwriting! We're going to test this, I want you to take this pad and pen and sign your signature so that I can't see what you're doing, and I'm going to write here on this pad. Don't rush, I'd like you to give me a good typical example of your signature, just imagine you're signing a specimen form for your bank, but make sure I can't see what you're
writing, that's right, cover it with your other hand."
The performer slowly and carefully writes, while occasionally looking up and
studying the volunteer, and then reveals his pad to show that by comparison, he
has amazingly drawn a fair approximation of the volunteers signature!!! (If you like, as the volunteer collects his cards you can say, Oh, you might not want to forget this..." and remove one of his cards which you have 'stolen' from your pocket to end on a laugh ;o)