From The Virtual Mirror (1994):

Like any public event, the Pentium debacle has spawned its share of humor.
Here's a sampling gathered from rec.humor and posted by Heinrich Goetz,
Glenn E. Lanier, Kenneth Hutchinson and David Sward (among others). 

Q: What's another name for that "Intel Inside" sticker they put on Pentiums?
A: A warning label. 

Q: Why didn't Intel call the Pentium the 586?
A: Because they added 486 and 100 on the first Pentium and got 585.999983605.

Q: What is Intel's follow-on to the Pentium?
A: Repentium. 

Q: What is the successor to the RU-486 birth control drug?
A: The RU-Pentium--it prevents cells from dividing properly 

Top Ten New Slogans for the Pentium:
 9.9999973251 It's a flaw, dammit, not a bug!
 8.9999163362 It's close enough, we say so!
 7.9999414410 Nearly 300 Correct Opcodes!
 6.9999831538 We fixed it, honest!
 5.9999535137 Redefining the PC--and mathematics as well
 4.9999999021 You don't need to know what's inside.
 3.9948245917 Division Considered Harmful
 2.9991523619 Why do you think they call it floating point?
 1.9999107513 We're looking for a few good flaws.
 0.9999999998 The Errata Inside

Q: How many Pentium designers does it take to screw in a light bulb?
A: 1.99904274017, but that's close enough for non-technical people. 

Q: How many Microsoft technicians do you need to screw in a light bulb?
A: None. Bill Gates will just define a new standard: Darkness (tm)