I have heard people making fun of the iPad because of the similarity to a feminine hygiene product, never mind that "pad" is a generic term that has many other uses. For one thing, it's sounds the same as very similar devices on Star Trek! Only according to Memory Alpha, the Star Trek wiki, it's spelled PADD, which stands for Personal Access Display Device. Most likely, this is really a backronym, just as another Apple product, the Lisa, supposedly stood for Local Integrated Software Architecture, even though Steve Jobs's daughter also happened to be named Lisa.
The name iPad may have been chosen so that all three devices have the same first two letters, iPod, iPhone and iPad. I think that from now on I'll just call them collectively iP.