Soak the clams in a large bowl with cold water and 1 teaspoon salt. Leave in water for 1 hour, then drain.
Cook the linguine in plenty of salted water until al dente, as instructed on the packet.
Meanwhile, in a large saucepan cook the garlic in oil until just sizzling and add clams and wine. Cover and cook for 5 to 7 minutes or until all the clams open. Shake the pan time to time to make sure the clams can move around. Remove from heat and let slightly cool. Reserve a few clams for the decorations and shell the others. Discard the valves. Strain the cooking liquid on a very fine sieve and keep it warm with the clams.
Place the pest in a bowl and diluite with a couple of spoons of the clams cooking liquid. Drain pasta and transfer in the pesto bowl, toss well and add more clam liquid if needed to make it most. Then add the shelled clams.
Divide in serving plates, decorate with the reserved in-shell clams and serve right away.