Ok, will try my best to share my knowledge about C702. Sorry the language as I'm not good at English. Maybe someone can edit for me later.

For this post, I'll show you what you can do with a C702;
1. Iron-man properties
-i'll show u pic only. view to believe.

2. GPS apps and how to use it at minimal cost possible.
-Firstly, SET ASSISTED START to NEVER, yes you may take longer locking time, but with no cost at all. Once connected, the second time is faster.
-Attempt gps connection at outdoor places only (in car still can lah), I heard ppl complain cant use gps in supermarket, lol.
-tracker [sports based apps; key in ur body weight and height and go jogging. It will plot ur route and estimate burned calories for you.]-geotagging image [basically set "add location" to on in camera settings, wait for the gps satellites to be connected first before take pic (got tiny green satellite on viewfinder)]-wayfinder navigator [SG and MSIA maps: credit to Blurjoey in C905 thread; copy the .wfd and put them in your "other folder" (no need create folder, just dump them inside)] however, it still require GPRS/3G data to download the route plan for you. Yalor, coz got option allow Tolls or not, Traffic info, Time etc. Depends on what you set lah. But still minimal, like 30 sen like that lah. Off automatic re-route if you want to save more. Coz once you got off track, it uses internet data to automatic re-plot new one lah.-maps [google maps, uses internet connection]
-other gps based application (download in SE applications wap site) ; PosItMe [send your location to other mobile phone using sms] can teach your son/daughter use this app, so that you'll know where they are. These days got a lot of kidnap cases, so it might be useful, who knows rite?
3. Browse internet using USB (Sony A200 phone)
-i'll show u the link only, credit to original author HERE

4. Camera
-got Face detection (will focus based on face to camera distance, normal focus only focus middle)
-modded camdriver available for C702, (change at ur own risk)
Code28h4p and N1 collaboration camdriver
-i will not teach you how to put, cos some say it will void warranty if you replace camdriver.

5. Other visual modding
-Flash menu HERE
sample of my flash menu