Get a more recent vim running in your terminal

update_vim.sh

# you'll need mercurial, gzip, a c compiler...
# though you could skip the mercurial if you download the source directly

#  get the latest source checkout
hg clone https://vim.googlecode.com/hg/ vim
cd vim

# if you already have the source, make sure it is up to date
## cd path/to/vim
## hg pull
## hg update default

cd src

# wont hurt to make sure things are clean
make distclean

# -prefix will put the build in your home dir, this is the important option
# the rest can be changed to taste, and don't represent an exhaustive list
# the listed ones will attempt to enable a gui for your platform, and allow 
# vim to be scripted with python.
./configure -prefix=$HOME --enable-gui=auto --enable-pythoninterp

make test
make -j2 # flag optional, attempts to parallelize compilation
make install

# add this line to .bashrc or .bash_profile to make sure the compiled version
# is found before the one distributed with OSX
export PATH=$HOME/bin:$PATH