There are plenty of freewares availabe in the market for k750i annd i am going to list top 5 applications for sony ericsson k750i.
1. Cellity freeSMS - already known for its free mobile twitter client - offers a free SMS service*: cellity freeSMS, which is available now! Sending and receiving short messages results in no fees through cellity. Your provider will not charge for any costly SMS.
2. scanR Scan, Copy and Fax - Scan business cards, fax documents and capture whiteboard notes. Just take photos, send them to scanR, and get clean, legible copies as PDF`s or vCards.
3. mig33 - It is a combination mobile instant messenger and international calling card service. You can chat to your buddies and meet new friends using the group chat rooms, profiling, photo sharing, MSN, Yahoo & AOL messenger
4. eBuddy Mobile Messenger - It is a multi-net application that you can use intuitively for the main thing that you want such an application for: Chat with your buddies.
5. FileExplorer - A java based file explorer for sony ericsson phones.
Compatibility List: Sony-Ericsson: D750, D750i, F500i, J200i, J210i, J220i, J230i, J300a, J300i, K300, K300a, K300i, K310, K508c, K508i, K510a, K510i, K550i, K600, K600i, K608i, K610, K610i, K618i, K700, K700c, K700i, K750, K750i, K790a, K790i, K800i, K800iv, M600i, P800, P900, P910, P910a, P910i, P990i, S700, S700i, S710a, T226, T230, T290a, T290i, T610, T616, T630, T637, T68, V600, V600i, V630i, W300, W300i, W550c, W550i, W600c, W600i, W700i, W710i, W800i, W810i, W810iv, W850i, W850iv, W880i, W900i, W950i, Z1010, Z300i, Z500, Z500a, Z520a, Z520i, Z530i.
If you have any compatibility problems leave a comment here.