Call this function with the following syntax from where you want display the comments on your template...

<?php latestcomments(5, 15, " said...", "[...]", 1, 1, 1); ?>

Save the following function in a separate file with a php extension and "include" that file from 
b2template.functions.php file.

<?php 
//By Michael H. Park (http://www.MichaelPark.net) 

function latestcomments($number = 10, $commentlength = 20, $authorstr = ' said...', $replacestr = '[...]', $show_date = 1, $show_time = 1, $popup = 1) { 
	global $tableposts, $tablecomments, $siteurl, $blogfilename, $querycount; 
	global $querystring_start, $querystring_equal, $querystring_separator;

	//strings you wish to exclude... to add more, use $excludeaway[] = "string";
	$excludearray[] = ":cool:";
	$excludearray[] = ":mad:";
	$excludearray[] = ":oops:";
	$excludearray[] = ":evil:";
	$excludearray[] = ":twisted:";
	$excludearray[] = ":roll:";
	$excludearray[] = ":wink:";
	$excludearray[] = ":idea:";
	$excludearray[] = ":arrow:";
	$excludearray[] = ":cry:";
	$excludearray[] = ":razz:";
	$excludearray[] = ":neutral:";
	$excludearray[] = ":mrgreen:";
	$excludearray[] = ":shock:";
	$excludearray[] = ":eek:";
	$excludearray[] = ":lol:";
	$excludearray[] = ":grin:";
	$excludearray[] = ":sad:";
	$excludearray[] = ":smile:";


	$joinquery = "SELECT ID, comment_ID, comment_author, comment_author_url, comment_content"; 
	
	//for date/time formatting, see www.mysql.com/doc/en/Date_and_time_functions.html
	if ($show_date == 1) {
		$joinquery .= ", DATE_FORMAT(comment_date, '%b. %D, %Y ') AS date"; 
	}
	if ($show_time == 1) {
		$joinquery .= ", TIME_FORMAT(comment_date, '%l:%i %p') AS time"; 
	}

	$joinquery .= " FROM $tableposts LEFT JOIN $tablecomments ON ID = comment_post_ID " . 
			 " WHERE comment_content NOT LIKE '%<trackback />%' AND comment_content NOT LIKE '%<pingback />%' " . 
			 " AND comment_content != '' " . 
			 " ORDER BY comment_date DESC LIMIT $number"; 
			 
	$joinresult = mysql_query($joinquery) or die(mysql_error()); 
	
	$querycount++; 
	
	while ($rows = mysql_fetch_array($joinresult)) { 
		$postID = $rows["ID"]; 
		$commentID = $rows["comment_ID"]; 
		$commentauthor = stripslashes($rows["comment_author"]); 
		$commentauthorurl = $rows["comment_author_url"]; 
		$commentcontent = strip_tags(stripslashes($rows["comment_content"])); 

		if (!empty($excludearray)) {
			foreach ($excludearray AS $exclude) {
				$commentcontent = str_replace($exclude, '', $commentcontent);
			}
		}

		if ($show_date == 1) { 
			$commentdatetime = $rows["date"]; 
		} 
		if ($show_time == 1) { 
			if ($show_date == 1) { 
				$commentdatetime .= ' @ ';
			}
			else {
				$commentdatetime = '@ ';
			}
			
			$commentdatetime .= $rows["time"]; 
		} 

		if ($popup == 1) {
			$link = ' <a href="'.$siteurl.'/b2commentspopup.php'.$querystring_start.'p'.$querystring_equal.$postID.$querystring_separator.'c'.$querystring_equal.'1'.$querystring_separator.'more'.$querystring_equal.'1#c'.$commentID.'"';
			$link .= ' '.'onclick="b2open(this.href); return false"';
		}
		else {
			$link = ' <a href="'.$siteurl.'/'.$blogfilename.$querystring_start.'p'.$querystring_equal.$postID.$querystring_separator.'c'.$querystring_equal.'1'.$querystring_separator.'more'.$querystring_equal.'1#c'.$commentID.'"';
		}			
		$link .= '>';

		if (strlen($commentcontent) > $commentlength) { 
			$link .= $replacestr.'</a>'; 
			$commentcontent = substr_replace($commentcontent, $link, $commentlength); 
		} 
		else { 
			$link .= '[Post]</a>'; 
			$commentcontent .= $link; 
		} 
		
		if (empty($commentauthorurl) || strlen($commentauthorurl) < 12) {
			echo $commentauthor.$authorstr; 
		}
		else {
			echo '<a href="'.$commentauthorurl.'" target="_blank">'.$commentauthor.'</a>'.$authorstr; 
		}
		
		echo "<br>\n"; 
		echo $commentcontent."<br>\n"; 
		if ($show_date == 1 || $show_time == 1) { 
			echo "<span style = \"font-size:9px\">on ".$commentdatetime."</span><br><br>\n\n"; 
		} 
		else { 
			echo "<br>\n"; 
		} 
	} 
}
?>