Both interweb and its close relative internetweb were created online and are mainly used as joking terms to imply ignorance or naivety about the Net, real or assumed. They’re not especially new: Wikipedia says that the first use of interweb was in an episode of Babylon 5 that was first broadcast in July 1994; internetweb goes back at least to 1995. I’ve also recently seen an extremely rare adjectival form of the former, interwebular (though the writer made it even rarer by using it as a noun). Writers in newspapers sometimes use these forms as deliberate errors to show their antipathy towards online matters or that they’re above having to bother with them. But enough examples of both interweb and internetweb have apppeared, seemingly used seriously, in recent years in in books and newspapers — too many for them all to be misprints — to make me wonder if uninformed users believe them to be the right way to refer to Web sites.
A third term that’s become popular since 2006 is intertube (my thanks to Seth Elgart for telling me about it). This is likewise used sarcastically by those who are familiar with the online world to suggest that somebody doesn’t know what they’re talking about. It sometimes appears as tubular interwebs. This came from the phrase series of tubes, which was used in the US Congress by Senator Ted Stevens in June 2006 while he was speaking about Internet matters. He was ridiculed for failing to understand the nature of the online system, though as he was arguing that the Net wasn’t a truck (lorry) but a series of tubes, he wasn’t creating a totally ridiculous analogy.