Sending small amounts of BTC to thousands?

[BitHits]

What would be the ideal tx size for this ?

I've been playing with it trying to find the best ratio of input to tx fee.

1 isnt optimal, 100's isnt optimal. 1000's is barely optimal and 2000+ at least gets me with a higher input the tx fee.

Like this http://blockchain.info/tx/24ee838c252c39b131f33202874b379e363e0d4e0d620581959a711dfaa84f05

[BlindMixerDR]

Your question is not clear. Do you mean, what is the best number of outputs in order to minimize the transaction fee per output?
The transaction you linked is almost a waste of bitcoins because the cost of redeeming each will be more than the transaction fee required to redeem. Each input to a transaction will add somewhere around 128 bytes to the transaction (I think). The fee is 0.0005 BTC per kB. So very small outputs are simply not cost-effective to redeem.

[Wardrick]

I think you need to make the question more clear. What I read it as is you want to send BTC to thousands of people (title). Maybe you'll get more help in the technical support section.