Good question! Never heard of it.
A quick websearch reveals:
SK-70 is a silicon lubricant, often used with condoms. It does not contain a spermicide
Sounds like it's just nice condom-safe lube.
Silicon-based lubricants and water-based lubricants are both safe for latex, and both common for sexual use. Water-based lubricants seem to be more common. Water-based lubes are better for female genitals from a perspective of discouraging infection. Silicon is apparently fine for guys though (and for the rest of women's bodies). Properties (advatages or disadvantages, depending of one's needs) of silicon lubes are that they don't dry up as fast as water lubes, and they don't wash away in water.
[This message has been edited by Eclipse (edited 10-05-2001).]