thejapanesepage has a lot:
#1 Reversed Kanji with the same pronunciation
事故
ji ko - (traffic) accident (USEFUL)
故事
ko ji - tradition, historical fact [submitted by Eduardo]
慣習
kan shuu - usual (historical) custom
習慣
shuu kan - custom, habit, manners (USEFUL)
名著
mei cho - famous book, masterpiece
著名
cho mei - well-known (USEFUL)
魚雷
gyo rai (ぎょらい) Torpedo
雷魚
rai gyo(らいぎょ) A type of fish - snakehead mullet (whatever that is...)
進行
shin kou(しんこう) progress, advance (USEFUL)
行進
kou shin(こうしん) march, parade (USEFUL)
和平
wa hei (わへい) peace
平和
hei wa (へいわ) peace (USEFUL)
画面
ga men(がめん)terminal screen, scene, picture, the field (in TV), photo (USEFUL)
面画
men ga(めんが)surface-drawing (NOT USEFUL)
社会
sha kai (しゃかい) Society (USEFUL)
会社
kai sha (かいしゃ)a business (USEFUL)
決議 (ketsu gi) a resolution (with suru - to resolve)
議決 (gi ketsu)
議会 (gi kai) an assembly
会議 (kai gi) a meeting (USEFUL)
議論
gi ron - an argument; a discussion
論議
ron gi - discussion; to discuss or talk about
楽器
gakki - a musical instrument (USEFUL)
器楽
kigaku - instrumental music
光栄
kou ei - honor, glory, privilege (USEFUL)
栄光
ei kou - glory (USEFUL)
海外 (kai gai) foreign countries (USEFUL)
外海 (gai kai)
数人
suu nin - Several People (USEFUL)
人数
nin zuu Number of people
材木
zai moku - wood, lumber, timber
木材
moku zai - lumber
実現
jitsu gen - realization (of a dream)
現実
gen jitsu - a reality, actual, real
#2 Reversed Kanji with a different pronunciation
日本
nihon (にほん) Japan (USEFUL)
本日
hon jitsu (ほんじつ) Today (USEFUL)
家出
ie de(いえで) running away from home, leaving home
出家
shukke(しゅっけ)entering the priesthood, priest, monk
力学
rikigaku(りきがく) mechanics, dynamics
学力
gaku ryoku(がくりょく)scholarship, knowledge, literary ability
男優
dan yuu(だんゆう) actor (USEFUL)
優男
yasa otoko(やさおとこ)man of gentle manners (USEFUL)
根性
kon jyou(こんじょう) will-power (vs), guts, temper, nature, spirit (USEFUL)
性根
shou ne(しょうね)character, nature
様子
you su(ようす)aspect, state, appearance (USEFUL)
お子様
o ko sama(おこさま)child (polite) (USEFUL)
凸凹
dekoboko - rough; uneven
凹凸
ou totsu - unevenness; uneven
敬愛
kei ai - respect & affection
愛敬
ai kyou - love & respect (USEFUL)
口出し
kuchi dashi - meddling, interference
出口
de guchi - exit (USEFUL)
切腹 seppuku - commiting suicide by cutting the stomach
腹切り
harakiri - same as above