This servicemenu sounds like a precedent contribution :
But I have fund this after write mine, and I prefer mine :-P
So, this service menu simply build the pdf file from a latex file by invoking pdflatex. The pdflatex processing is achived in a temporary directory, so only the final pdf file is created in the working directory.
copy the script pdflatextmp in a directory that is in your path (~/bin/ for a user install, or /usr/local/bin/ for system wide install)
copy the servicemenu pdflatex.desktop in the subdirectory apps/konqueror/servicemenus of the kde dir (maybe /usr/share for a system wide install or ~/.kde/share for a user install).