1. A stable, uniform, nitroglycerin-based topical cream comprising: a) about 0.1 to about 3% by weight of nitroglycerin; b) about 5 to about 24% by weight of a penetration enhancer; c) about 60% to about 90% by weight of water, having a pH of about 6.0 to about 9.0; d) about 0.5 to about 3% by weight of a thickener; and e) about 0.4 to about 2% by weight of an emulsifier. 2. The cream of Claim 1 wherein the amount of said nitroglycerin is about 0.1 to about 1% by weight. 3. The cream of Claim 1 wherein the amount of said penetration enhancer is about 8 to about 13% by weight. 4. The cream of Claim 1 wherein said penetration enhancer is at least one member selected from the group consisting of propylene glycol, glycerine, isopropyl palmitate, isopropyl myristate, laurocapram, and mixtures thereof. 5. The cream of Claim 1 wherein the amount of water is about 75 to about 88% by weight. 6. The cream of Claim 1 wherein the amount of said thickener is about 1.1 to about 2% by weight. 7. The cream of Claim 1 wherein said thickener is at least one member selected from the group consisting of methylcellulose, polyethylene glycol, acrylic add polymers and mixtures thereof. 8. The cream of Claim 1 wherein said emulsifier is an amount of about 0.4 to about 1% by weight. 9. The cream of Claim 1 wherein said emulsifier is a non-ionic surface active agent. 10. The cream of Claim 1 wherein said emulsifier is at least one member selected from the group consisting of polyethylene glycol alcohol ether, polyoxyethylene acid ester, and partial ester of sorbitol or anhydride thereof; and mixtures thereof. 11. The cream of Claim 1 having a pH of about 6.0 to about 9.0. 12. The cream of Claim 11 containing an alkyl ethanolamine or buffer or both. 13. The cream of Claim 11 that contains at least one member selected from the group of flavorings, fragrances, preservatives, coloring agents, topical anesthetics, and mixtures thereof. 14. A method for treating a male patient suffering from erectile dysfunction which comprises topically applying to the genital area of said patient an effective amount of the topical cream of Claim 1. 15. The method of Claim 14 for treating a patient suffering from erectile dysfunction by applying about 0.1 to about 3 grams of said cream. 16. A method for treating a female patient suffering from anorgasmia which comprises topically applying to the vaginal area of said patient an effective amount of the topical cream of Claim 1. 17. The method of Claim 16 for treating a patient suffering from anorgasmia by applying about 0.1 to about 1.10 grams of said cream. 18. A method for treating a patient suffering from a microvascular disease which comprises topically applying to the afflicted areas of said patient an effective amount of the topical cream of Claim 1. 19. The method of Claim 18 wherein said microvascular disease is peripheral neuropathy. 20. The method of Claim 18 which comprises applying about 1 to about 3 grams of said cream. 21. A method for treating a patient suffering from a wound or surgical incision which comprises topically applying to the area within the vicinity of said wound or incision of said patient an effective amount of the topical cream of Claim 1. 22. The method of Claim 21 which comprises applying about 0.2 to 1 gram of said cream. 23. A method for preparing the topical cream of Claim 1 which comprises: admixing said thickener and about 80 to about 90% of the water and heating to provide a first solution; admixing said emulsifier, about 15 to about 85% of said penetration enhancer, the remainder of said water with heating to provide a second solution; admixing said first solution and said second solution to provide a cream base; and admixing said nitroglycerin, the remainder of said penetration enhancer and the cream base to obtain said topical cream. 24. The method of Claim 23 wherein said first solution and said second solution are admixed at a temperature of about 50 degree C or lower.