Piotr, I'm not a licensed amateur yet, I don't have a callsign. However I'm on the #highaltitude IRC channel on Freenode with all the other UKHAS members, so, if there's a flight on spacenear.us heading my way, there's a slim chance it will pass me unnoticed. 
I was ready for the SP5NVX pico balloon last weekend, but unfortunately it didn't float for long.
Yesterday evening I did warn Latvian radio enthusiasts about this ORION flight, but maybe because of the short notice or early hours, or wind, or some other excuse they didn't join in tracking this time, they have tracked a few flights before. However the Estonian guy (he's on that channel too) got a few packets. Just give us something to track and we have this area covered.
I was ready for the SP5NVX pico balloon last weekend, but unfortunately it didn't float for long.Yesterday evening I did warn Latvian radio enthusiasts about this ORION flight, but maybe because of the short notice or early hours, or wind, or some other excuse they didn't join in tracking this time, they have tracked a few flights before. However the Estonian guy (he's on that channel too) got a few packets. Just give us something to track and we have this area covered.