If you are a believer, Paul indicates in Philippians 1:22-24 (and Jesus in Luke 16:19-31) that your spirit, shorn of your body, lives in the presence of Christ:
For to me to live is Christ, and to die is gain. 22 If I am to live in the flesh, that means fruitful labor for me. Yet which I shall choose I cannot tell. 23 I am hard pressed between the two. My desire is to depart and be with Christ, for that is far better. 24 But to remain in the flesh is more necessary on your account.
To "depart" from the body, then, is to reside with Christ.
Ultimately, however, this intermediate spiritual state is not "heaven." At the resurrection, your body (changed from perishable to imperishable) and spirit will be reunited. You, together with all of God's people, will live in the New Heaven and New Earth (Revelation 21) illumined eternally by the light of Christ's presence and you will never die again (1st Corinthians 15th).
For a good discussion of the "intermediate state" click here and listen to Dr. RC Sproul's short lecture on the topic.