[Puzzle] Only Connect - Connecting Wall

In the UK, a fantastic brainy game show has surfaced over the past few years, called "Only Connect."
The game centers around common threads between 4 items... not unlike TriBond, but with a spike in difficulty.

One of the most intriguing rounds in the game is the "Connecting Wall", where 16 items are placed in front of a team, and they must choose the 4 groups of 4, one group at a time. There is usually an overlap in some answer possibilities, but there is a definitive solution.

This wall was featured on one of the final matches, and is one of the more challenging sets. Can you identify the 4 groups, AND why they are grouped in that manner?

1984	6	496	180
8128	32	28	491.67
8 1/2	273.15	300	147
Seven	0	2010	21

There is a mix of subject matter in this grid - It's not all math.

Discuss openly, make guesses and assumptions - But don't give away too much, too soon.

Well, 1984, 2010, 8 1/2 and Seven are all titles of books and/or movies. Other than that I'm stumped.

How about:
1. Four items that contain characters other than digits
2. Four items that have "0" as last character
3. Four items, that are positive numbers under 100
4. Everything else

:)

Quote: Nareed

Well, 1984, 2010, 8 1/2 and Seven are all titles of books and/or movies. Other than that I'm stumped.

21 too :)

Quote: weaselman

Quote: Nareed

Well, 1984, 2010, 8 1/2 and Seven are all titles of books and/or movies. Other than that I'm stumped.

21 too :)

Don't forget 300.

If one of the groups truly is "Book/Movie" titles, which 4 items fit? Or more importantly, which fit in other categories?

Do the rules specify that the groups must be formed from complete rows and/or columns, or can you pick 4 items from anywhere in the grid?

Quote: MathExtremist

Do the rules specify that the groups must be formed from complete rows and/or columns, or can you pick 4 items from anywhere in the grid?

anywhere in the grid

This show is also presented by the lovely poker pro Victoria Coren

I have a plausible grouping for 3 groups, but the 4th doesn't yet make any sense. I know for a fact what one group is, at least:

<spoiler here>
0, 32, 273.15, and 491.67 are all related to temperature. 0 and 32 are the freezing point of water in C and F, respectively, and 273.15 and 491.67 are the degrees above absolute zero of the freezing point of water, also in C and F respectively.
also, I'm less convinced about this one, but:
Seven, 21, 28, and 147 are all evenly divisible by 7.
</end spoiler>

Quote: Dween

1984	6	496	180
8128	32	28	491.67
8 1/2	273.15	300	147
Seven	0	2010	21

I hope this isn't giving away too much. We learned from the WizardOfEngland's puzzle that 147 is a perfect score in Snooker. We also know 300 is perfect in bowling, and 21 in blackjack (actually a blackjack beats 21, but let's not get too picky). Normally they say 29 is a perfect score in cribbage, but that counts the one point for "knobs" or "heels," which is more like a bonus point than part of your hand. So, I think it could be argued that 28 is a perfect score in cribbage. Maybe there is another game I don't know about that fits this pattern.