  The possibility to determine the pLambda scattering length from the
final-state interaction in the reaction pp->pKLambda is investigated
experimentally. From a transversely polarized measurement, the K analyzing
power (A_N) which, in principle, allows one to extract the spin triplet
scattering length is studied. An unexpected energy dependence of the
forward/backward symmetric part of A_N is found. The influence of N*-resonances
on the pLambda invariant mass spectrum is investigated by exploiting the large
acceptance for the process pp->pKLambda->pKppi and is found to be the main
source of uncertainty for determining the pLambda scattering length.
