my google query, was 'include thread teaser in title attribute'
theres a bunch of em
My simplest answer is to download a copy of vbulletin and read the code.
not knowing the data structure, just giving 'duh' column names
something like
select postheading firstpost href from postlist where readflag=nul
and output
echo '<a href=\''.$href.'\' title=\''.substr ( $firstpost, 0, 150 ).'\'>.$postheading.'</a>';
from the database