Typical value of I2C pull-up's is 2k2 - 10k. It's value also depends on the bus capacitance.
In following thread:
"http://www.8052.com/forum/read.phtml?id=24862&top=" Erik
suggested to look at Philips.
I'd like to add some other:

http://www.philipslogic.com/i2c/
http://www.philipslogic.com/products/collateral/i2c/

Vaclav