Reverse Beacon Network measures your signal!

If you are a CW operator, there is an excellent way of getting a measure of your signal strength around the world: http://www.reversebeacon.net

It is a network of ham stations using CW Skimmer to automatically pick you call and measure its strength in dB compared to the noise level. For example, tonight I called CQs and had a few QSOs on the 20m band with 100W and my quite new delta loop antenna. These reverse beacon stations heard me:

I had a QSO session on 20m at 9pm and these "robots" heard me.

The spots are uploaded almost in realtime, so you can utilize this in order to check the propagation. The propagation conditions may be checked from many other sources as well, but this reverse beacon network is especially suitable for antenna tests; sometimes it's difficult to find a fellow ham at a certain time in a certain continent to help you :)

So, this hint is only for CW operators. Digimode operators have other options, like pskreporter.info and JT65 HF RB(=Reverse Beacon). SSB operators have miscellaneus net stream services for listening to their own voices...this is something I haven't tried yet.