Is there any special meaning or significance to the different forms that a Buddha statue or sculpture might take?
I have two myself, one is like the main picture on the Buddha article on Wikipedia, and the other is the more stereotypical Buddha, but with his hands up in the air.
Are they both just a “Buddha”, or do they have unique meanings?
Yes, as far as the hands go we are talking about mudras, “symbols of deeper meaning” as that sites put them.
I wouldn´t be surprised if this gesture/posture symbolisms extend to the whole figure.
Last time I went to Ayuthaya, a city to the North of Bangkok awash in temples, my GF took me to one (actually ten) where people were pouring oil in small lamps in front of different representations of the Buddha, each one represented a different day of the week and showed the Buddha in different poses and attitudes. However I have no clue whether those where standard symbolims or not.
Absolutely these all mean different things. The buddha iconography is a teaching aid, and each position means something. Tibet by Victor Chan, a guidebook, has an extensive explanation on the different Tibetan buddhist buddhas and what they mean.
I got a really hideous painting. Turns out it is the wrathful (re whoop ass) incarnation of one of the standard buddhas.
Get yourself a coppy of Alice Getty’s The Gods of Northern Buddhism. I think of it as The Field Guide to the Buddhas. and I;'m not being irreligious.
There is a rich tradition of iconography associated with Buddhist figures, and there are a great many types of Buddhas – not all representing the same figure, by any means – and their gestures. All mean different things, and the resulting panoply of possible types is really confusing.
In much the same way, states of the Saints in Europe have a rich iconography. You can tell from their attributes who a particular saint is supposed to be. St. Erasmus has a ship’s wheel. St. Barbara her tower, and so on. See The Penguin Dictionary of Saints or some simuilar guide to see what statue is supposed to be what saint, and why. The Buddha figures are as many and varied as the Catholic saints.
This column by Cecil may be of interest: Why do statues of Buddha have long earlobes? What’s the difference between fat Buddha and regular Buddha?
Hey BuddhaBuddhaBuddhaBuddhaBuddhaBuddhaBuddhaBuddha! Sa-WING, Buddha!
Sorry. Couldn’t resist that.
Nor this: ‘Sold! To the highest Buddha!’ Totally worthless points to whomever knows where I got that, without looking it up.
Yeah. What they said.
All right, a Buddha call!
Shall we build a Buddha mousetrap? It could be our Bread and Buddha.
Mmm… Buddha-licious.
You forgot Big J with his enigmatic two fingers up and tight salute.
You´re so not going to Nirvana. 
This is a very, very common misconception but the “stereotypical Buddha”, if he looks likes this, isn’t Buddha but Hotei, a semi-legendary Buddhist saint.
Right, not the Buddha at all. And many, but not all, Thais are actually offended by Hotei. But since he’s more of a Chinese thing, you do see him occasionally in Chinatown or the homes of some Chinese-Thai families. Not common at all here, though.
