It's the biggest day in the year for Apple fans, with Steve Jobs due on stage at the Macworld conference in San Francisco at 5pm to reveal which of the various products rumoured to be on the way come to fruition. If you believe the Mac rumour sites, and even Wikipedia, we’re about to get bombarded with anything from a new MacBook with a solid-state disk, to a 3G version of Apple's iPhone.

But not every tale told is one told true. Not even in Macland, where Jobs' reputed "reality distortion field" is legendary enough to have its own acronym: RDF.

Here are three examples, including a couple of late-entry rumours that popped up just yesterday.

For a short time on Monday, Wikipedia posted a bullet list that purported to be a rough outline of Jobs' expected Macworld presentation. (He goes on stage at 5pm, GMT; PC Advisor will have the news from his keynote as it happens.) That 'presentation' outline quickly vanished from the online encyclopedia, but lives on at

The outline was chock-o-block with juicy details, including the clever 'draft 5.0' notation, and enough believable items - Steve talks up iPod sales, Steve unveils iPhone software development kit (SDK) - to make it convincing. It's an old trick; mix in things that are true with those that may not be. iPod sales do remain strong; Apple has already said that the SDK will be out soon.

But who at Apple would spell the company's boffo blow-out 'MacWorld' with a capital 'W' when everyone knows - including the people who printed the banners that went up over the weekend - that it's a lowercase letter, as in 'Macworld'.

Base 2, that's all you need to know. A screen grab posing as a quick shot of the Apple online store quickly made the rounds, supposedly spelling out the configuration details and price of what wags have said will be called the 'MacBook air'. The picture was presumably made after someone on the server side at Apple accidentally clicked the 'publish' button on a secret page showing the 'air' - a lighter, thinner notebook that relies on a solid state drive built from flash RAM, rather than the spinning platters of a traditional hard drive.

But as pointed out on Monday, something smells about the specs. Specifically, the 'screenshot' lists SSD (solid state drive) options at 60GB and 80GB. Trouble is, Samsung, the leader in the notebook SSD arena and a major supplier to Apple, doesn't sell its 2.5in and 1.8in drives in either 60GB or 80GB capacities. Instead, the blocks of memory come in densities of 8GB, 16GB, 32GB, 48GB or 64GB. (And no, we don't know how the not-a-base-2 number of '48' snuck in there.)