if money is not aq concern - do i pick the d90 or d300?

wanting more professional quality photos - blow up pictures large enough to put on th wall as art.

If money is no concern, choose the Canon 5D Mk. II. kinda hard to argue 1080p video full frame and 21 MP. The new D90 is pretty sweet though.

If you are going to print really large then the resolution is a wash (both have 12.3 Mp effective, though the D300 has a hair larger sensor -- 13.1 vs. 12.9 Mp). However, the D300 offers 14-bit uncompressed RAW (NEF) files vs. only 12-bit compressed NEF in the D90, so assuming you are using RAW to capture and process the highest quality you can, the D300 is a clear winner. And, of course, the D300 has better low-light images, more features, more hardened case, etc. Same true for the new D300s, which keeps the sensor but speeds up everything else and adds a few more features.

If you want comparable or better performance and significantly higher resolution for those big prints, but at a comparable price point, then you might want to look at the new Canon 7D (18 Mp).