I have contours (about 5000 polylines) in shapefile and I need to interpolate those with Spline. But Spline function in ArcGIS 10 can only interpolate points, and my contours are polylines. I hope that anyone has a solution to my problem. Thanks a lot!
You are looking for the Topo to Raster tool (in Spatial Analyst and/or 3D analyst extensions). I think there is also a "Feature to Point" tool available with an ArcInfo license.