  We present predictions on the angular power spectrum of CMB fluctuations due
to extragalactic point sources (EPS) by using a method for simulating realistic
2D distributions of clustered EPS. Both radio and far--IR selected source
populations are taken into account. To analyze different clustering scenarios,
we exploit angular power spectra of EPS, $P(k)$, estimated either by data
coming from currently available surveys or by means of theoretical predictions.
By adopting the source number counts predicted by the Toffolatti et al. (1998)
evolution model -- capable of accounting well for the available data at radio
cm wavelengths -- we are able to reproduce current data on the two--point
angular correlation functions, $w(\theta)$, of radio sources. We can confirm
that the detection of primordial CMB anisotropies is not hampered by undetected
clustered sources at frequencies $\leq 150-200$ GHz. On the other hand, our
current findings show that at higher frequencies the clustering signal could
severely reduce the detectability of intrinsic CMB anisotropies, thus
confirming previous theoretical predictions. We also show that unsubtracted EPS
can account for the excess signal at high multipoles detected by recent CMB
anisotropy experiments. Moreover, the additional power due to the clustering of
sources gives rise to a small but not negligible contribution to the same
excess signal. As a final result, we also present an example of a currently
feasible {\it realistic map} of EPS at 70 GHz, by taking into account data on
bright detected sources as well as the previously quoted model for number
counts.
