Where can I buy one of these pentalobe tools

looks like tamper-resistant torx in the 5 lobed variety. These are and have been commonly used on many of the European cars in various applications such as motor, brakes, lights and interior trim. These should be about the right dimension and can give you an idea which size you might be looking for. The screws that Apple installed on the iPhone 4 is T1

Size Inch point to point [in] Metric point to point [mm]

T1 .031 .81

T2 .036 .93

T10 .107 2.74

T15 .128 3.27

T20 .151 3.86

Looks like very limited availability :) http://www.traderscity.com/board/product...

and http://www.8starshop.com/en/12-in-1-comp...

Good luck and do not forget to change the screws to something a little more manageable....

Wiha Pentalobe Screwdrivers will be available in November 2013. KC Tool already has them listed and will email you as soon as they arrive. These will surely be the best Pentalobe screwdriver you can buy for $8. They have all of the sizes for iPhone, macbook and macbook air and a 6 piece set.

I decided to quit fooling around and just get a set that will open just about anything. I was very pleased with the quality of these bits. At $28, I thought it was a deal: http://www.amazon.com/dp/B000PLZJFK/ref=...

This one looks like a better deal for $11.50

http://www.amazon.com/Neiko-100-Piece-Se...

I get all my tools from Harbor Freight tools they have just about every tool imaginable and great prices as well. They have a pretty big selection of precision drivers. If you are in the US i suggest you check there before buying online to save yourself some hassle and waiting time. Also sears has a big selection of torx drivers but you need the 5 lobe "torx plus" they might have these drivers as well.

i bought mine on ebay i looked for "iphone 4 torx"

macbook air one: http://cgi.ebay.com/ws/eBayISAPI.dll?Vie...

Where can I get a 1/4" bit version so I can use it in my standard security bit driver set? Wiha doesn't seem to have any, though I asked if they can "find" any. I like it for iPhone, MBA, and the gamebit ones as well, if at all possible.

There are many sellers on eBay that have the pentalobe screwdriver for sale that will work on the iPhone 4 and 4s back glass screws. In a lot of cases the eBay sellers include the pentalobe screwdriver with the purchase of a back iPhone 4/4s back cover or a front screen. There are sellers that have the driver by itself for a minimal coast. If you want to get the driver quickly I suggest you buy from a "US" seller instead of a seller that is in another country because it takes much longer to get the driver from them in most cases.Hope this helps.