Finally I found working streams of most Finland live TV stations that are watchable on N900. They are hosted by anywheretv.fi.

TV1
http://82.203.211.81:1261/hfmbygsn.flv

TV2
http://82.203.211.81:1262/hhmtnkcg.flv

MTV3
http://82.203.211.81:1266/bscbtnsq.flv

Nelonen (TV4)
http://82.203.211.81:1276/mysebhpf.flv

SubTV
http://82.203.211.81:1267/cmewdcpl.flv

FST
http://82.203.211.81:1264/hhmtnkcg.flv

Teema
http://82.203.211.81:1263/hhmtnkcg.flv

JIM
http://82.203.211.81:1268/cmewdcpl.flv

Urheilukanava (stream down as of writing this)
http://82.203.211.81:1269/vvyufwbu.flv

I tried these on N900 and they work on KMPlayer using Mplayer as backend. At peak times (right now...) these seem to become choppy but let's hope they improve their bandwidth in the future. (Earlier today they played much better.)

If you are on PC and want to watch Finnish TV stations... you can also register (free) on anywheretv.fi and watch all these channels on PC, free, anywhere in the world! (Flash player required.)

I have no idea how long it takes before these URL:s are changed... I guess we'll find out by that time...

EDIT: Links are still working so most likely they will stay like that for some time being. Over the last two days I watched some TV during my lunch break over Tmobile 3G connection. It works flawless as long as their server is not too busy.

Note that the TV2 has only audio. Let's see if they fix it sometimes.

The links works also with a PC when played with VLC. (I did add them to my home theater PC playlist.)