This is an updated shell script / AppleScript for opening a new tab in your current directory (or the specified directory). The last version was for the pre-tabbed version of Terminal.
#!/bin/sh –
if [ $# -ne 1 ]; then
PATHDIR=`pwd`
else
PATHDIR=$1
fi
if [ $# -ne 1 ]; then
PATHDIR=`pwd`
else
PATHDIR=$1
fi
/usr/bin/osascript <<-EOF
activate application "Terminal"
tell application "System Events"
keystroke "t" using {command down}
end tell
tell application "Terminal"
repeat with win in windows
try
if get frontmost of win is true then
do script "cd $PATHDIR; clear" in (selected tab of win)
end if
end try
end repeat
end tell
EOF