I suggest using SymbianSigned.com to sign your apps. I know many people don't trust websites with their IMEI, but it's a trusted and well known site. Plus, it's using a 128-bit VeriSign certificate, so you won't send your IMEI in plain text.
You should stay away from websites which make you download and install software. You'll most likely end up with adware or trojans and your applications won't get correctly signed anyway.
I've already tried that... And it tells me the following:
"
FAILURE: Submitted .sis file uses a UID that is not allocated to the account holder matching this email address (0xa0008e00 0xa0008e01 )
"
Afterwards, I tried the GenialSiS, but the guy closed down...
I then tried a SignSIS, but it asked me for a .cer, which I don't have, so, I couldn't sign it so far...
But, anyway thanks a lot for the quick reply, and, I'll keep trying!
I don't know what type of device you own, but if it's a Nokia, you could always try one of the hacks that allow you to run unsigned installations. Or, you could look for the SafeCert package, which I don't have a link for, that can give you a dev certificate file for SignSIS.
I've got a Nokia N78.
I'm not particularly inclined to hack my phone for it'd violate the warranty, and I'm not sure I'm willing to do that.
But, anyways, thanks a lot!
I'll give the two links a deeper look when I'm at home.