There are a few names that aren't gender specific:
Pat
Terry
Gail
Michael
Chris
Sam (I've heard it used for Samuel and Samantha)
Kerry
Kim
...Mark.... 
Another popular one: Jamie.
Lord he'p us, I found a list of the current top 50 unisex names:
. Addison (Girls #12)
2. Ashley (Girls #18)
3. Ashton (Boys #121)
4. Avery (Girls #38)
5. Bailey (Girls #82)
6. Cameron (Boys #53)
7. Carson (Boys #89)
8. Carter (Boys #65)
9. Casey (Boys #336, Girls #466)
10. Corey (Boys #289)
11. Dakota (Boys #226, Girls #267)
12. Devin (Boys #109)
13. Drew (Boys #244)
14. Emerson (Girls #290)
15. Harley (Girls #415, Boys #592)
16. Harper (Girls #297)
17. Hayden (Boys #76)
18. Hunter (Boys #54)
19. Jaiden/Jayden (Boys #168, Girls #176)
20. Jamie (Girls #263)
21. Jaylen (Boys #184)
22. Jesse (Boys #110)
23. Jordan (Boys #48, Girls #130)
24. Justice (Boys #432, Girls #542)
25. Kai (Boys #229)
26. Kelly (Girls #248)
27. Kelsey (Girls #195)
28. Kendall (Girls #148)
29. Kennedy (Girls #115)
30. Lane (Boys #319)
31. Logan (Boys #19)
32. Mackenzie (Girls #65)
33. Madison (Girls #4)
34. Marley (Girls #146)
35. Mason (Boys #35)
36. Morgan (Girls #46)
37. Parker (Boys #103)
38. Peyton (Girls #60, Boys #130)
39. Piper (Girls #172)
40. Quinn (Boys #280)
41. Reagan (Girls #141)
42. Reese (Girls #154)
43. Riley (Girls #39, Boys #106)
44. Rowan (Boys #340, Girls #469)
45. Ryan (Boys #18)
46. Shane (Boys #174)
47. Shawn (Boys #195)
48. Sydney (Girls #49)
49. Taylor (Girls #22)
50. Tristan (Boys #81)
Story: when our older daughter was born we lived in Texas, and I told my father in law that we were going to name her "Anastasia Roberta..." so that we could call her "Nasty-Bob" for short.
I actually had him for about 2 seconds before he caught on.
Such is the power of Texas.
