In the news

select
username,
count(*) as numposts
from
posts p
inner join
users u
on
p.userid = u.id
where
p.id = 123456 and p.created > '5-aug-2011'
group by
u.id
order by
numposts desc

more like:

SELECT username, COUNT( * )
FROM post
WHERE threadid =13146
AND dateline >=1312156800
GROUP BY username
ORDER BY 2 DESC
LIMIT 0 , 30

output (top 30):

Mankind is doomed 334
EEI 284
horatio 243
nuknow 212
the lush 202
whatok 144
Oliver Schick 131
Dammit 124
Pistanator 115
TS 107
spotter 104
clintsmoker 84
Day-Moe 75
prole art threat 75
CasaSteve 72
hippy 66
Buffalo Bill 64
Jimm 63
ExTra 59
dooks 57
catfood 57
dicki 56
CowHen 56
Manc Ronnie 56
adoubletap 55
wolfsangle23 53
neu 52
hugo7 49
nailbrush 48
Markyboy 45