Here is the complete numerical spring training roster for the 2006 Cubs, players and coaches. I've also listed the five retired numbers so you can see at a glance which numbers are "vacant" at this time.
Non-roster players in italics
1 Augie Ojeda
2 Gene Clines (coach)
3 Marquis Grissom
5 Ronny Cedeno
6 Sonny Jackson (coach)
7 Todd Walker
8 Michael Barrett
9 Juan Pierre
10 Ron Santo (retired)
11 Jacque Jones
12 Dusty Baker (manager)
13 Neifi Perez
14 Ernie Banks (retired)
15 Jerry Hairston
16 Aramis Ramirez
17 John Mabry
19 Matt Murton
22 Mark Prior
23 Ryne Sandberg (retired)
24 Henry Blanco
25 Derrek Lee
26 Billy Williams (retired)
28 Michael Restovich
31 Greg Maddux
32 Jerome Williams
33 Glendon Rusch
34 Kerry Wood
35 Chris Speier (coach)
36 Gary Matthews (coach)
38 Carlos Zambrano
39 Dick Pole (coach)
40 Todd Wellemeyer
41 Larry Rothschild (coach)
42 Jackie Robinson (retired by MLB)
43 Michael Wuertz
44 Roberto Novoa
45 Will Ohman
46 Ryan Dempster
47 Scott Eyre
48 Scott Williamson
49 John Koronka
51 Jose Reyes
52 Sean Marshall
53 Rich Hill
54 David Aardsma
55 Ryan Theriot
56 Brian Dopirak
57 Scott Moore
58 Geovany Soto
59 Juan Lopez (coach)
60 Bobby Brownlie
61 Carlos Marmol
62 Bob Howry
63 Carmen Pignatiello
64 Casey McGehee
65 Brandon Sing
66 Adam Greenberg
67 Angel Guzman
68 Felix Pie
70 Jae-kuk Ryu
71 Buck Coats
72 Raul Valdez
74 Jake Fox
76 Randy Wells
78 Dennis Anderson