So, this is the solution to my "bee or hoverfly" quiz.

PLEASE GO TO DOWNLOAD FOR BETTER DETAILS, OTHERWISE YOU MIGHT NOT SEE THE STRUCTURES I'M TALKING ABOUT!

Top two rows are hoverflies, third row are bees. I added a fourth row here, to show some additional characteristics.

~hepiladron,~tikayl,~JupiterAdept,~Henriksen and ~Miracidium got them all right. `sags was right too: The Bees are the ones that sting !!
The Hovers are the ones than can't be bothered!

So what's the whole point, you may ask?

Hoverflies are among the most frequent visitors to flowers in the garden, and also among those most photographed. They are, however, often mistakenly believed to be bees or wasps. So I decided to submit a more educational piece which explains some of the major differences between the two.

Why would you want to know?
First, you don’t want me to go complaining on your photos because you called a hoverfly a bee . Second, if you are afraid of bees and wasps because they might sting you, you have a very good reason to read on: If you know that the yellow-blackish insect hovering in front of your face is a harmless fly with no stinger, you’ll be able to go about your business much more relieved .

The short version: How do I know it can't be a bee or wasp?

(1) It has very short antennae with a bristle (bees have longer antennae that look quite different).
(2) The mouthparts look different. Flies often have fleshy pads at the end, bees don't. In bees, the mandibles (jaws) are usually visible, in flies they are reduced.
(3) It has only one pair of wings; there is a pair of knob-like structures instead of the hindwings (bees have four wings, though it's often not easy to see).
!The easiest characteristic to go buy is usually the antennae!

The longer version
Hoverflies
Hoverflies are a large family of flies with some 800 species in Europe and 5,000 worldwide.
They go by the scientific family name of “Syrphidae”. Hoverflies can look very similar to bees, bumblebees or wasps, but with a bit of practice it is very easy to tell them apart from the latter. As they are flies, they belong to the insect order Diptera, together with other flies, mosquitos, gnats, and midges. Diptera means “two wings”, which refers to a major characteristic that sets the Diptera apart from other winged insect orders, which usually have four wings (though one or both pairs can be reduced in some cases). The Diptera’s second pair of wings, the hind wings, are reduced to halteres, small knob-like structures also known as balancers or poisers. They are flapped rapidly in flight to maintain stability.
Flies (suborder Brachycera, a subdivision in the Diptera order) have shortenend antennae with a maximum of 8 segments each (Brachycera means "shortened horn" ). Most “advanced” flies have only 3 antennal segments: 2 basal segments and a bristle called “arista”.Their mouthparts are characteristically suctorial and many have large fleshy pads with drainage canals that enable efficient liquid uptake.

Bees, wasps and bumblebees
These are in a different order of insects, the Hymenoptera. Ants and sawflies are in the same order. Hymenoptera, like most other winged insects, have two pairs of wings. Both are membranous, and the smaller hindwings are usually connected to the forewings by small hooks. Hymenoptera have chewing mouthparts, except for bees, which have a long proboscis (a complex "tongue" ) that enables them to obtain the nectar from flowers. The antennae of most bees are made up of thirteen segments in males and twelve in females.

More info:
Tree of Life: Diptera
Tree of Life: Brachycera
Wikipedia: Fly
The Garden Safari: Hoverflies

Wikipedia: Hymenoptera
Hymenoptera