I did a script in order to do what you are trying to do, but for a different kind of phone.
I used mencoder, which is a part of Mplayer (link). It has the advantages of being free, and able to play nearly anything you throw at it.
You should check out this question, I created it in order to centralize mencoder commands.
Here's the command for my phone :
mencoder "input.avi" -ovc lavc -oac
lavc -lavcopts acodec=mp3:abitrate=128
-vop scale=400:240 -ffourcc DX50 -o "output.avi"
Someone else mentionned this command for iphones, but I haven't tested it :
mencoder "$file" -subcp cp1252
-sub-fuzziness 1 -subfont-autoscale 3 -subfont-blur 2 -subfont-outline 2 -aid 1 -vf scale=480:320:0:0:0.00:0.50,dsize=480:320,harddup
-sws 2 -of lavf -lavfopts format=mp4 -ovc x264 -x264encopts bitrate=768:qcomp=0.6:qp_min=10:qp_max=51:qp_step=4:vbv_maxrate=1500:vbv_bufsize=2000:level_idc=30:dct_decimate:me=umh:me_range=16:keyint=250:keyint_min=25:nofast_pskip:global_header:nocabac:direct_pred=auto:nomixed_refs:trellis=1:nobrdo:nobime:nob_pyramid:nob_adapt:no8x8dct:noweight_b:bframes=0:threads=auto:frameref=1:subq=6
-af channels=2 -oac faac -faacopts br=128:mpeg=4:object=2:tns:raw -o
Once you have found the mplayer commands that work well with your phone, you can add them in a python script, allowing you to batch convert lots of files :
Stack Overflow : Using Python to execute a command on every file in a folder.