Hello brothers, uncles all the master ...^_^

Please help all of you.
I was again in trouble ya its very high cpu load, but the beginning does not problematic, it is good to use nginx now .. uh .. keep up the cpu load specifications for vps
RAM = 768M
SWAP = 1567M
CPU = 2

This config my.cnf

[mysqld]
#skip-name-resolve
safe-show-database
#old_passwords
back_log = 50
skip-innodb
max_connections = 500
key_buffer_size = 1536M
myisam_sort_buffer_size = 64M
join_buffer_size = 1M
read_buffer_size = 1M
sort_buffer_size = 2M
table_cache = 5000
thread_cache_size = 384
wait_timeout = 20
connect_timeout = 10
tmp_table_size = 64M
max_heap_table_size = 64M
max_allowed_packet = 64M
net_buffer_length = 16384
max_connect_errors = 100000
thread_concurrency = 4
concurrent_insert = 2
table_lock_wait_timeout = 30
read_rnd_buffer_size = 786432
bulk_insert_buffer_size = 8M
query_cache_limit = 3M
query_cache_size = 64M
query_cache_type = 1
query_prealloc_size = 262144
query_alloc_block_size = 65536
range_alloc_block_size = 4096
transaction_alloc_block_size = 8192
transaction_prealloc_size = 4096
default-storage-engine = MyISAM
max_write_lock_count = 8

[mysqld_safe]
nice = -5
open_files_limit = 8192

[mysqldump]
quick
max_allowed_packet = 64M

[myisamchk]
key_buffer_size = 144M
sort_buffer_size = 16M
read_buffer_size = 16M
write_buffer_size = 16M

for cpu load images like this ..
http://video.eurekapage.com/files/photos/1319808563e83d46_o.jpg

Please help the master ...