just to share my findings, i can use synaptic to use apt-fast script to act as man in the middle, so it will use axel to accelerate downloading packages.
before this, apt-fast can only be use in terminal, now can use it directly using synaptic. perfect for lazy-to-type-in-terminal as me

now to the point, first open /usr/bin/apt-fast using any text editor as root. apt-fast script is installed by default for me (using 2011.09 kde minime version), dont really know about other version. search for it in synaptic if its not already installed.
btw edit the file, search for this string (line 24) and edit it, from
y) if apt-get install axel -y --force-yesto
y) if apt-fast install axel -y --force-yesthen this string, line 42
apt-get -y --print-uris $@ | egrep -o -e "(ht|f)tp://[^\']+" > apt-fast.list && cat apt-fast.list | xargs -l1 axel -ato
apt-fast -y --print-uris $@ | egrep -o -e "(ht|f)tp://[^\']+" > apt-fast.list && cat apt-fast.list | xargs -l1 axel -athen both line 45 and line 50
apt-get $@;to
apt-fast $@;then save it.
after done saving, rename the apt-fast into apt-get and the original apt-get file in the same folder as apt-fast. make sure both renamed file is executable and ur done.
now start synaptic, try downloading any big package and see how the speed is

also if u use apt-get command from terminal from now own, its actually the apt-fast script and its works just fine. all original apt-get command eg apt-get install, remove, dist-upgrade etc works.
do take note that before upgrading the actual apt and apt-fast package itself (if any update come after u do this), u need to rename back both file, apt-get into apt-fast and the other way around. also that i wouldnt be responsible if u borked ur machine, it exploded and ur cat is catch on fire from ur exploded machine because doing all this. do it on ur own risk.on the light note, i've been using this for months without any problem whatsoever
