Wifi SMS Communication Manager (Free) - See below for limits.
This app provides a web interface for SMS text message communication. You can send and receive text messages via your computer through your phone. They will appear to the receiving person as if you used your phone (new messages still appear on your phone). The app contains a simple web server running on port 8080 (by default). Configurable password protection for the website to stop others on the same network using or viewing your SMS conversations.
The web page layout is simple, with tabs for each person you are communicating with. No special plugins to download or special software needed on your PC! You can select a person from the contacts list from your device or enter a new number (enter numbers only). New messages are polled (poll time is configurable) every few seconds.
Messages are logged to a folder (.wifiSMS) on your sdcard.
Configuration options:
1. Port number to run web server on (8080).
2. Use notifier? (Pops up a JavaScript box when a new message arrives - this usually flashes your browser if you are in a different window or minimized).
3. Polling time (seconds)
4. Use Password? Y/N and Password value. If selected you must enter a password to access the web server.
Tested on the latest Internet Explorer, FireFox and Chrome on Windows 7 and Windows XP.
Note: Will only work if your computer (PC) and Android are on the same Wifi network. Please do not expect it to work across networks or through firewalls.
** The free version is intended for you to try the app before you buy to see if it works for you. New SMS messages are limited to sending 5 characters. For the full version look for "Wifi SMS Communication Manager" in the Android market **