This is a follow up to the info from Maher above....
"I read the Market comments about Seek Droid and it says the following, which doens't seem all that great: Be careful though - the remote lock feature basically just adds a standard lock screen to your phone. It won't take effect while the phone is in use."
FYI for those not familiar with Seek Droid: After logging into
www.seekdroid.com with your username and secret code, you chose Lock (obviously, right!). You're prompted to enter a new lock code. A brief message appears: "Attempting to lock device". It then changes to "Sending message to Google, please wait." A Google map appears on most of the screen. If your phone already has a lock code (pattern lock or numeric), it will change it to the new code. If you don't have a lock, it will apply one. Interestingly, Seek Droid does not immediately include a message on your computer that the code was applied successfully. I've sent a command to change the code and it changed within 2 mins, but the "Sending message to Google" popup remained for 5+ minutes after it actually locked. Eventually, "Device Locked" appeared. Also, the Google Map does not change or adjust to the phone's location using the lock command. You must click the Locate button to change the map.
Based on the info from Maher, I tested 2 scenarios: (1) phone is on and unlocked (screen is on...I'm navigating through the phone and opening/closing apps...not letting the phone lock), and (2) during a call. In the first cases, Seek Droid changed the code. As I was playing with the phone, the screen went blank...when I woke it up, the new lock code was required.
In the second case, I connected a call and stayed connected for 5 mins. The phone never received or accepted the command to change the code.
So...it appears Seek Droid works with the phone on...but not during a call.
**UPDATE**: I originally posted that the lock command did not work even after ending a call...if the command was sent during a call. I confirmed this with 3 different tests. I recommended that you re-send the lock command over an extended period with the hope that one of the commands might reach the phone while its not on a call. After further testing, I had instances where I sent a command during a call, hung up, then 1-2 minutes later the lock command arrived and the phone locked. I did not have to re-send it like the original tests suggested.