I'm not sure why they say that there. AFAIK the 1 comes from a version field indicating Bitcoin (vs. Namecoin etc) by convention. I've never seen a 3... address in use or displayed. I don't think it's because they "ran out" since addresses are generated randomly. I could be wrong though as I don't know all the innards and history.

You can actuallly run oclvanitygen at the same time as mining. I did it and it worked and dropped some % of mining speed. It did seem to be a bit unstable or maybe that was just pushing my OC a bit hard. I had better results when disabling the GPU from mining.

As discussed in the new thread on vanity address outsourcing the vanity addresses that start with 3 will be much easier (less computation) to create.  This will lead to the possibility of longer vanity addresses for those that start with 3.

What do you mean?

As discussed in this thread https://bt.irlbtc.com/view/56839.0 we are not talking about creating a vanity address using the current software that "just happens to start with a 3" we are talking about creating a proper vanity address that starts with 3 - that is - the hash of a one of two key script where one of the keys is a valid public key and the other key is a bogus "filler" public key.  Therefore you would end up with a vanity address that starts with a 3 which is the proper hash of a proper script that will work properly.

To do this would take a new version of the vanitygen (and GPU version of vanitygen) that does all the proper calculations in order to create the proper script and proper hash of the script.

The nice thing is that each trial in the search for the vanity address would be much faster.  In this future system the algorithm is:

1) Create a valid keypair
2) Create a random invalid/bogus public key (basically a nonce).  Note the private key is unknown/unknowable
3) Create a valid "use one of these two keys" script with the valid public key and the bogus public key as the two parameters
4) Properly hash the script (much easier that a public key calculation)
5) Check for the vanity pattern, if it matches quit, otherwise go to step 2)

Note that each trial is now just the time it takes to generate a random number and take the hash of the script!

OOOOOOOOOOOOOOOO actually reading the bolded part makes a big difference. 

I just made a new years resolution to learn to read more carefully.

samr hasn't logged into the forum since August. You might need to get the source yourself, try to set up a compile environment for it, and then modify the software so it searches for proper minikeys (only 1 in 10,000 or so mini-sized keys match the requirements if I recall) and then does the phrase check. Because of this additional difficulty, a normally 1-day phrase might take you 20 years though...

I wasn't able to get GPU working in linux, but it turns out my cluster of CPUs was enough to create the address I really wanted :

    1QBDLYTDFHHZAABYSKGKPWKLSXZWCCJQBX

Am I really the first person that has done this?  FreeMoney didn't even recognize it as a BTC address.  At the very least, people should recognize that one when they see it

A donation is on its way!

This problem gets exponentially harder, the fewer characters you choose to have in your final address.  In this case, I only wanted upper-case letters, which limits each character in the final address to one of 24 characters out of 58 (26 letters in alphabet minus 'I' and 'O').   If your address was only one letter after the '1', you would have to generate 2.4 addresses (58/24, on average) to get all uppercase letters.  If it was two letters, you'd have to generate 5.8 (2.4^2) addresses on average before finding it.  Etc.  So for an address with 32 letters, you're talking 2.4^32 guesses before finding such an address (on average).

At 300,000 keys per second in vanitygen, it should take about two months (I calculate 70 days) to find such an address as I have in my signature (on average).

If you now instead change it to all numbers, you've now limited yourself to 9/58 characters instead of 24/58 (10 digits minus '0').  If you repeat the calculation using 58/9, it will take 6.4^32 guesses.  At the same key generation rate, I calculate it would take 3,022,041,992,597,561 days to find such an address.

So the answer to your questions is... no

So there's a chance...

I like how you sent btc from the address to prove you own it. Very nice.

Why is there an assumption that the checksum is any different than the rest of the letters?  The address is created from 25 bytes.  The first byte is always '\x00' which corresponds to the first '1' you see in every main-network Bitcoin address.  So we will ignore that one...

But the following 20 bytes are a hash, which means it's all essentially-random bits.  Then, the checksum is just 4 more bytes, which are also a hash... which means it's essentially random, too.  When I say "essentially-random", I mean from the perspective of what characters will be used in the Base58 address, all letters are equally likely for all positions, except maybe the very first character after the '1', and that's for reasons that are difficult to explain...

But the point is that the address is created from a sequence of 24 bytes (addr + checksum) which are all essentially random, so why would some letters be more difficult to match than others?   If you want more information about how addresses are computed, click the bottom link in my signature.  There's a diagram halfway down that shows how addresses are generated from the public key. 

-Eto