[Davey]

1) Open up the editpost template and find this line:
<td bgcolor="{secondaltcolor}"><normalfont><input type="text" class="bginput" name="title" value="$postinfo[title]" size="40" maxlength="85" tabindex="1"></normalfont></td>
2) Change:
maxlength="85"
to the value of the maximum length of characters you want in the subject.
3) Save the editpost template.
4) Open up the newreply template and find this line of code:
<td bgcolor="{secondaltcolor}"><normalfont><input type="text" class="bginput" name="title" value="$title" size="40" maxlength="85" tabindex="1"></normalfont> <smallfont>(Optional)</smallfont></td>
5) Change:
maxlength="85"
to the value of the maximum length of characters you want in the subject.
6) Save the newreply template.
7) Open up the newthread template and find this line:
<td bgcolor="{secondaltcolor}"><normalfont><input type="text" class="bginput" name="subject" value="$subject" size="40" maxlength="85" tabindex="1"></normalfont></td>
8) Change:
maxlength="85"
to the value of the maximum length of characters you want in the subject.
9) Save the newthread template.
10) Open up the template threads_editthread and find the line:
<td bgcolor="{secondaltcolor}" width="27%"><normalfont><input type="text" class="bginput" name="title" value="$threadinfo[title]" size="50" maxlength="85"></normalfont></td>
11) Change:
maxlength="85"
to the value of the maximum length of characters you want in the subject.
12) Save the threads_editthread template.
13) Open the threads_merge template and find:
<td bgcolor="{secondaltcolor}" width="27%"><normalfont><input type="text" class="bginput" name="title" value="$threadinfo[title]" size="50" maxlength="85"></normalfont></td>
14) Change:
maxlength="85"
to the value of the maximum length of characters you want in the subject.
15) Save the threads_merge template.
That's it.
I'm sure Xenon can come up with a simpler way to do it through a PHP file edit, but this is the only way I'd have done it.

Dave.

PS: To do it with the calendar event's too:
16) Open the calendar_enterevent template and find:
<td bgcolor="{firstaltcolor}"><input type="text" class="bginput" name="subject" value="$subject" size="50" maxlength="50" tabindex="4"></td>
17) Change:
maxlength="50"
to the value of the maximum length of characters you want in the subject.
18) Save the calendar_enterevent template.