Does the classical 5V <--> 3.3V bidirectional MOSFET interfacing solution exist as a DIP package? Or is the commopn way to place discrete MOSFETs in your circuit? In that case, what are some common low cost through-hole devices that you can recommend for this application? I realize this question has been asked in a few variations already, but I'm looking for practical implementation guidance here.
The NXP P82B96 bidirectional I2C buffer IC comes in DIP8, among other packages.
Yes, some people do use discrete MOSFETs; for example, the Sparkfun Logic Level Converter.
There are a few ICs that do bidirectional I2C interfacing, but as far as I know they are all surface-mount. The Bi-directional 3.3v <-> 5v level shifting... thread mentions a few of them. Alas, I don't know of any that are in a DIP package.
Pretty much any nFET can handle the relatively low power and speed required for I2C interfacing; the critical spec seems to be "Vgs(th)". Sparkfun uses a BSS138, a low-cost surface-mount nFET with Vgs(th) of 1.5 V at 1 mA.
TI Makes a part that will do this:
TXS0102 - 2-bit bi-directional level translator