Check out obscuring snow in combination with snowsight (both from Frostburn). A 30-foot radius of obscuring snow that moves with the caster and lasts 1 hour/level (!!!). Combine with snowsight (druid 1, 1 hour/level) cast on everyone in the party and, Voila!, mobile zone of blindness that nerfs all your enemies yet provides no hindrance to the party. Talk about broken.
Or how about boreal wind, also from Frostburn. Can be read to deal up to 15d4 per round for 1 round plus 1 round/2 levels, plus blows back opponents up to 3 feet per caster level.
Yeah, Frostburn has some problems...
